| Authors | Title | Year | Journal | Reftype | Note | Link |
|---|---|---|---|---|---|---|
| L.S. Cederbaum, J. Zobeley & F. Tarantelli | Giant Intermolecular Decay and Fragmentation of Clusters | 1997 | Phys. Rev. Lett. 79, 4778 |
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| Abstract: {In sharp contrast to molecules, electronic states of clusters with an excited intermediate-shell electron can efficiently decay via an intermolecular Coulombic mechanism. Explicit examples are presented using large scale ab initio propagator calculations. The mechanism is illustrated and its generality is stressed.} | ||||||
BibTeX:
@article{Cederbaum97,
author = {Cederbaum, L. S. and Zobeley, J. and Tarantelli, F.},
title = {{Giant Intermolecular Decay and Fragmentation of Clusters}},
journal = {Phys. Rev. Lett.},
publisher = {American Physical Society},
year = {1997},
volume = {79},
issue = {24},
pages = {4778},
numpages = {4},
note = {theory},
doi = {https://doi.org/10.1103/PhysRevLett.79.4778}
}
|
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| J. Zobeley, L.S. Cederbaum & F. Tarantelli | Highly excited electronic states of molecular clusters and their decay | 1998 | J. Chem. Phys. 108, 9737 |
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| Abstract: {Highly excited electronic states of molecular clusters with intermediate-shell vacancies are calculated and analyzed using large scale ab initio Green's function calculations. In sharp contrast to molecules, an intermolecular Coulombic mechanism has been found to lead to an ultrafast decay of singly and doubly ionized states with vacancies in the inner-valence region. Small hydrogen-bonded (HF)n clusters (n=2--4) have been selected as explicit examples to illustrate the proposed decay process, which does not occur in the HF monomer. The decay mechanism and the main factors that exercise an influence on it are discussed. The corresponding decay widths are estimated in selected cases, showing that the lifetimes of the states are of the order of few femtoseconds. } | ||||||
BibTeX:
@article{Zobeley98,
author = {Zobeley, J. and Cederbaum, L. S. and Tarantelli, F.},
title = {{Highly excited electronic states of molecular clusters and their decay}},
journal = {J. Chem. Phys.},
publisher = {AIP},
year = {1998},
volume = {108},
issue = {23},
pages = {9737},
numpages = {14},
note = {theory},
doi = {https://doi.org/10.1063/1.476448}
}
|
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| J. Zobeley, L.S. Cederbaum & F. Tarantelli | Intermolecular Coulombic Decay of Molecular Clusters: Identification of the Decay Mechanism Using a New Hole-Population Analysis | 1999 | J. Phys. Chem. A 103, 11145 |
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| Abstract: {Singly ionized states of molecular clusters with an inner-valence vacancy have recently been shown to undergo an efficient electronic decay. The mechanism of the decay, which is absent in the isolated molecules that build up the clusters, is proposed to be of intermolecular Coulombic nature. As explicit example to further investigate this new decay process, the valence ionization spectrum of the HF(H2O)2 cluster is computed with the ADC(3) one-particle Green's function method. In the inner-valence part of the spectrum, characteristic dense line bundles due to the ultrafast electronic decay of the corresponding cationic states are observed. A new hole-population analysis method for the very many computed cationic states is presented. This method allows for a quantitative measure and characterization of the hole localization pattern of the cationic states. The dense line bundles which mimic the continuous decay distributions in our finite basis set approach are analyzed in detail. The resulting intermolecular character of the states confirms the recently proposed intermolecular Coulombic mechanism for the electronic decay in molecular clusters. The decay leads to dicationic states with two vacancies located on neighboring monomer units.} | ||||||
BibTeX:
@article{Zobeley99,
author = {Zobeley, J. and Cederbaum, L. S. and Tarantelli, F.},
title = {{Intermolecular Coulombic Decay of Molecular Clusters: Identification of the Decay Mechanism Using a New Hole-Population Analysis}},
journal = {J. Phys. Chem. A},
publisher = {American Chemical Society},
year = {1999},
volume = {103},
issue = {50},
pages = {11145},
numpages = {16},
note = {theory},
doi = {https://doi.org/10.1021/jp992677i}
}
|
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| R. Santra, L.S. Cederbaum & H.-D. Meyer | Electronic decay of molecular clusters: non-stationary states computed by standard quantum chemistry methods | 1999 | Chem. Phys. Lett. 303, 413 |
|||
| Abstract: {Cationic inner valence states of molecular clusters have recently been shown to decay via a novel intermolecular mechanism. To compute the lifetimes and energies of the non-stationary states, we advocate the strategy to use standard quantum chemistry procedures augmented by complex absorbing potentials. A new and efficient complex absorbing potential has been implemented to take the non-compact geometry of a molecular cluster into account. Numerical results obtained for (HF)2+ are presented.} | ||||||
BibTeX:
@article{Santra99,
author = {Santra, R. and Cederbaum, L. S. and Meyer, H.-D.},
title = {{Electronic decay of molecular clusters: non-stationary states computed by standard quantum chemistry methods}},
journal = {Chem. Phys. Lett.},
publisher = {Elsevier},
year = {1999},
volume = {303},
issue = {3-4},
pages = {413},
numpages = {7},
note = {theory},
doi = {https://doi.org/10.1016/S0009-2614(99)00226-2}
}
|
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| R. Santra, J. Zobeley, L.S. Cederbaum & N. Moiseyev | Interatomic Coulombic Decay in van der Waals Clusters and Impact of Nuclear Motion | 2000 | Phys. Rev. Lett. 85, 4490 |
|||
| Abstract: {It is demonstrated that excited van der Waals systems can relax by electron emission via a novel interatomic mechanism. The process is analyzed by means of extensive ab initio calculations of potential energy surfaces and electronic decay rates. The electronic emission, taking place on the same time scale as the motion of the atomic nuclei, is accompanied by interesting dynamical effects amenable to experimental observations. These effects arise as a consequence of the weak chemical bond in van der Waals clusters and the Coulomb repulsion pattern originating from electron emission.} | ||||||
BibTeX:
@article{Santra00_1,
author = {Santra, R. and Zobeley, J. and Cederbaum, L. S. and Moiseyev, N.},
title = {{Interatomic Coulombic Decay in van der Waals Clusters and Impact of Nuclear Motion}},
journal = {Phys. Rev. Lett.},
publisher = {American Physical Society},
year = {2000},
volume = {85},
issue = {21},
pages = {4490},
numpages = {4},
note = {theory},
doi = {https://doi.org/10.1103/PhysRevLett.85.4490}
}
|
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| R. Santra, J. Zobeley & L.S. Cederbaum | Inner-valence ionization of molecular anions and ultrafast relaxation by electron emission | 2000 | Chem. Phys. Lett. 324, 416 |
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| Abstract: {Relaxation mechanisms following inner-valence ionization of CN- are investigated using ab initio quantum chemistry methods. Due to a severe failure of the molecular orbital picture, there is a relatively large number of electronic states that are excited by ionization in the inner-valence regime. Most of these states are found to decay by electron emission, resulting in the formation of vibrationally bound CN+. General conclusions can be drawn concerning larger molecular anions.} | ||||||
BibTeX:
@article{Santra00_3,
author = {Santra, R. and Zobeley, J. and Cederbaum, L. S.},
title = {{Inner-valence ionization of molecular anions and ultrafast relaxation by electron emission}},
journal = {Chem. Phys. Lett.},
publisher = {Elsevier},
year = {2000},
volume = {324},
issue = {5--6},
pages = {416},
numpages = {7},
note = {theory},
doi = {https://doi.org/10.1016/S0009-2614(00)00681-3}
}
|
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| R. Santra, J. Breidbach, J. Zobeley & L.S. Cederbaum | Parallel filter diagonalization: A novel method to resolve quantum states in dense spectral regions | 2000 | J. Chem. Phys. 112, 9243 |
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| Abstract: {A parallel version of D. Neuhauser's filter diagonalization algorithm is presented. In contrast to the usual procedure of acting with a set of narrow filter operators on a single or just a few initial vectors, parallelizability is achieved by working with a single, broad filter operator and a correspondingly large number of initial vectors. Apart from the obvious speedup in computation time, there is no need for communication between the processors involved in the computation. Furthermore, because a significantly reduced number of matrix vector multiplications is needed per initial vector, parallel filter diagonalization is numerically more stable than the single processor approach. It is argued that this method is particularly attractive for calculating eigenvectors of the large-scale secular matrices arising in quantum chemistry, especially in dense spectral regions. An application to dense state distributions of a cationic molecular cluster serves as an illustrative example. This is the first time filter diagonalization is used as a tool for ab initio electronic structure calculations.} | ||||||
BibTeX:
@article{Santra00_2,
author = {Santra, R. and Breidbach, J. and Zobeley, J. and Cederbaum, L. S.},
title = {{Parallel filter diagonalization: A novel method to resolve quantum states in dense spectral regions}},
journal = {J. Chem. Phys.},
publisher = {AIP},
year = {2000},
volume = {112},
issue = {21},
pages = {9243},
numpages = {10},
note = {theory},
doi = {https://doi.org/10.1063/1.481545}
}
|
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| J. Zobeley, R. Santra & L.S. Cederbaum | Electronic decay in weakly bound heteroclusters: Energy transfer versus electron transfer | 2001 | J. Chem. Phys. 115, 5076 |
|||
| Abstract: {Inner-valence ionized states of weakly bound systems like van der Waals clusters can efficiently decay by electron emission. The mechanism of the decay, which does not occur in the isolated monomer units constituting the clusters has recently been shown to be of intermolecular/interatomic nature. This intermolecular/interatomic Coulombic decay (ICD) mechanism prevails in many systems ranging from hydrogen-bonded molecular clusters to atomic rare gas clusters. In the present paper we extend our previous studies to weakly bound heteroclusters built up of monomer units of largely differing energetics. It is shown that, as soon as the double ionization potential of a monomer unit is lower in energy than the ionization potential of the initially created inner-valence vacancy on a neighboring monomer unit, an additional electronic decay process can take place. In contrast to the ICD mechanism, which involves an efficient energy transfer between the monomer units, this second process is essentially based on an electron transfer process. It is therefore termed electron-transfer mediated decay (ETMD). We have analyzed the mechanisms of the electronic decay processes taking place following inner-valence ionization in weakly bound heteroclusters in an exemplary study of the NeAr dimer. The involved electronic states have been calculated using ab initio Green's function techniques. The lifetime of the inner-valence Ne(2s-1)Ar vacancy has been estimated and partitioned according to the contributions of the two decay channels based on a perturbation-theoretical description of the decay process. As a result, the lifetime of the inner-valence resonance state is estimated to be of the order of 10-100 fs, the specific value strongly depending on the internuclear separation of the monomers. The ICD process is shown to be by far the dominant decay channel at distances corresponding to bound states of the dimer. With decreasing internuclear separation the ratio of the ETMD and ICD decay widths quickly increases over several orders of magnitude. } | ||||||
BibTeX:
@article{Zobeley01,
author = {Zobeley, J. and Santra, R. and Cederbaum, L. S.},
title = {{Electronic decay in weakly bound heteroclusters: Energy transfer versus electron transfer}},
journal = {J. Chem. Phys.},
publisher = {AIP},
year = {2001},
volume = {115},
issue = {11},
pages = {5076},
numpages = {13},
note = {theory},
doi = {https://doi.org/10.1063/1.1395555}
}
|
||||||
| R. Santra, J. Zobeley, L.S. Cederbaum & F. Tarantelli | Intermolecular Coulombic decay of clusters | 2001 | J. Electron Spectrosc. Relat. Phenom. 114--116, 41 |
|||
| Abstract: {Following inner-valence ionization of a cluster, the system can relax by ultrafast electron emission. In contrast to Auger decay this novel process is intermolecular. It is characterized by an efficient Coulombic energy transfer mechanism between monomers in the cluster. As an example, we present an analysis of the hydrogen fluoride trimer, based on extensive ab initio computations.} | ||||||
BibTeX:
@proceedings{Santra01_1,
author = {Santra, R. and Zobeley, J. and Cederbaum, L. S. and Tarantelli, F.},
title = {{Intermolecular Coulombic decay of clusters}},
journal = {J. Electron Spectrosc. Relat. Phenom.},
series= {The 8th International Conference on Electronic Spectroscopy and Structure: (ICESS8)},
publisher = {Elsevier},
year = {2001},
volume = {114--116},
pages = {41},
numpages = {7},
note = {theory},
doi = {https://doi.org/10.1016/S0368-2048(00)00256-5}
}
|
||||||
| R. Santra, J. Zobeley & L.S. Cederbaum | Electronic decay of valence holes in clusters and condensed matter | 2001 | Phys. Rev. B 64, 245104 |
|||
| Abstract: {Following innervalence ionization of a cluster, the system can relax by electron emission, a phenomenon called intermolecular Coulombic decay. This process is characterized by an efficient energy transfer mechanism between neighboring monomers in the cluster. A theoretical description within the framework of Wigner-Weisskopf theory is developed, thus enabling a detailed analysis of the decay process. The main result of the formal treatment, a simple, approximate expression for the electronic decay width of an innervalence hole state, is applied to investigate the effect of cluster size. On the basis of extensive ab initio calculations, pronounced size effects are found in the concrete example of neon clusters. The decay lifetime decreases in a monotonic fashion from hundred femtoseconds in Ne2 down to less than ten femtoseconds in Ne13. Suggestions are made how to facilitate the experimental observation of intermolecular Coulombic decay in clusters and condensed matter.} | ||||||
BibTeX:
@article{Santra01_3,
author = {Santra, R. and Zobeley, J. and Cederbaum, L. S.},
title = {{Electronic decay of valence holes in clusters and condensed matter}},
journal = {Phys. Rev. B},
publisher = {American Physical Society},
year = {2001},
volume = {64},
issue = {24},
pages = {245104},
numpages = {10},
note = {theory},
doi = {https://doi.org/10.1103/PhysRevB.64.245104}
}
|
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| R. Santra & L.S. Cederbaum | An efficient combination of computational techniques for investigating electronic resonance states in molecules | 2001 | J. Chem. Phys. 115, 6853 |
|||
| Abstract: {Calculating electronic resonance states in molecules is a serious challenge to theory, because the treatment of both the scattering and the many-electron problem is a formidable task. A very promising approach, known as CAP/CI, consists of the combination of a complex absorbing potential with the method of configuration interaction. In this paper we propose the combination of three distinct computational techniques in order to boost the performance of CAP/CI. A complex absorbing potential that can be adjusted flexibly to the geometry of the molecular scattering target is presented and its representation in a Gaussian basis set is discussed. To handle the large-scale complex symmetric eigenvalue problem arising in CAP/CI, a subspace projection method is employed and its validity is shown. We advocate the use of parallel filter diagonalization for calculating the eigenvectors required in the projection step. The proposed techniques are applied to determine the lifetime of an autoionizing, inner-valence excited state of Ne2+.} | ||||||
BibTeX:
@article{Santra01_2,
author = {Santra, R. and Cederbaum, L. S.},
title = {{An efficient combination of computational techniques for investigating electronic resonance states in molecules}},
journal = {J. Chem. Phys.},
publisher = {AIP},
year = {2001},
volume = {115},
issue = {15},
pages = {6853},
numpages = {9},
note = {theory},
doi = {https://doi.org/10.1063/1.1405117}
}
|
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| N. Moiseyev, R. Santra, J. Zobeley & L.S. Cederbaum | Fingerprints of the nodal structure of autoionizing vibrational wave functions in clusters: Interatomic Coulombic decay in Ne dimer | 2001 | J. Chem. Phys. 114, 7351 |
|||
| Abstract: {The removal of an inner-valence electron from neutral neon clusters leads to autoionization and subsequent fragmentation of the cationic clusters in accordance with the interatomic Coulombic decay mechanism discovered recently. Using non-Hermitian quantum scattering theory we investigate this process in detail for the Ne dimer. We show that a pronounced structure can be observed when measuring the autoionizing electron or the Ne+ kinetic energy distributions. This phenomenon is associated with the properties of the vibrational autoionizing resonance states of the electronically excited cationic dimer. By suppressing coherence among the different vibrational autoionizing resonances, or by selectively exciting one of them, the structures in the kinetic energy distributions become more pronounced. It is demonstrated that these structures reflect the nodal structure of the wave functions of the autoionizing vibrational states most populated by the initial ionization of the neutral neon dimer. In a coherent decay we encounter substantial interference effects, but the nodal pattern of the corresponding wave functions is still present. The kinetic energy distributions are generally very sensitive to details of the potential energy curves of clusters.} | ||||||
BibTeX:
@article{Moiseyev01,
author = {Moiseyev, N. and Santra, R. and Zobeley, J. and Cederbaum, L. S.},
title = {{Fingerprints of the nodal structure of autoionizing vibrational wave functions in clusters: Interatomic Coulombic decay in Ne dimer}},
journal = {J. Chem. Phys.},
publisher = {AIP},
year = {2001},
volume = {114},
issue = {17},
pages = {7351},
numpages = {10},
note = {theory},
doi = {https://doi.org/10.1063/1.1361070}
}
|
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| R. Santra & L.S. Cederbaum | Non-Hermitian electronic theory and applications to clusters | 2002 | Phys. Rep. 368, 1 |
|||
| Abstract: {Electronically excited cations, generated by inner-valence ionization of small molecules, relax in general by dissociation and photon emission. Autoionization is forbidden for energetic reasons. The situation changes fundamentally in an inner-valence ionized cluster, which releases its excess energy by emitting an electron. This novel process, referred to as Intermolecular Coulombic Decay, is characterized by an efficient energy transfer between monomers in the cluster. The decay is ultrafast, taking place on a femtosecond time scale. Theoretical tools are developed to predict the properties, in particular lifetimes, of molecular systems undergoing electronic decay. These methods are applied to study the relaxation of inner-valence holes in clusters. In order to enable a treatment of the scattering and the many-particle problem with standard electronic correlation methods for bound states, a complex absorbing potential is added to the Hamiltonian. Conceptual as well as practical aspects of this procedure are discussed in detail.} | ||||||
BibTeX:
@article{Santra02,
author = {Santra, R. and Cederbaum, L. S.},
title = {{Non-Hermitian electronic theory and applications to clusters}},
journal = {Phys. Rep.},
publisher = {Elsevier},
year = {2002},
volume = {368},
issue = {1},
pages = {1},
numpages = {117},
note = {theory},
doi = {https://doi.org/10.1016/S0370-1573(02)00143-6}
}
|
||||||
| I.B. Müller, J. Zobeley & L.S. Cederbaum | Comparison of electronic decay of valence ionized fluorinated carbanions and their acids | 2002 | J. Chem. Phys. 117, 1085 |
|||
| Abstract: {The ionization and double-ionization spectra of fluorinated carbanions of various chain lengths are compared with those of their corresponding acids. For the acidic systems we find a dramatic relative shift of the double-ionization spectra to higher energies due to the presence of just one additional proton. The impact of the proton on the ionization spectra is also important, but results in only half of the double-ionization spectra's shift. A molecular electronic decay mechanism is found to be operative in the valence region of the molecules under investigation. The impact of this decay is more substantial for the anions. The threshold for electronic decay (i.e., the first double-ionization potential) is at much lower energy for the anions than for the acids. Interestingly, the localization pattern of the holes in the decay channels is, in contrast to the decay threshold, only a little affected by protonation. We also compare the impact of electron correlation effects on the ionization and double-ionization spectra of the series of fluorinated carbanions and of their acids.} | ||||||
BibTeX:
@article{Mueller02,
author = {Müller, I. B. and Zobeley, J. and Cederbaum, L. S.},
title = {{Comparison of electronic decay of valence ionized fluorinated carbanions and their acids}},
journal = {J. Chem. Phys.},
publisher = {AIP},
year = {2002},
volume = {117},
issue = {3},
pages = {1085},
numpages = {13},
note = {theory},
doi = {https://doi.org/10.1063/1.1484388}
}
|
||||||
| S. Scheit, L.S. Cederbaum & H.-D. Meyer | Time-dependent interplay between electron emission and fragmentation in the interatomic Coulombic decay | 2003 | J. Chem. Phys. 118, 2092 |
|||
| Abstract: {The electronic decay of the Ne2+ cation by electron emission is studied. This interatomic Coulombic decay (ICD) follows inner valence ionization of the neon dimer and the decay rate depends strongly on the internuclear distance. The time-dependent theory of wave packet propagation is applied allowing to follow the evolution of the decay process in time. The impact of nuclear dynamics on the decay spectrum is investigated. Among others, the spectrum corresponding to the decay of the 22Σu+ electronic state of the Ne2+ cation is calculated at different times. Its characteristics are found to be influenced considerably by the nuclear motion. A pronounced oscillatory structure appears: Its origin is explained and related to the interatomic nature of the ICD process. Particularly enlightening for the understanding of the ICD process is the analysis of the total energy distribution in the final system resulting after the fragmentation of the Ne22+ dication, produced by the ICD of Ne2+.} | ||||||
BibTeX:
@article{Scheit03,
author = {Scheit, S. and Cederbaum, L. S. and Meyer, H.-D.},
title = {{Time-dependent interplay between electron emission and fragmentation in the interatomic Coulombic decay}},
journal = {J. Chem. Phys.},
publisher = {AIP},
year = {2003},
volume = {118},
issue = {5},
pages = {2092},
numpages = {16},
note = {theory},
doi = {https://doi.org/10.1063/1.1531996}
}
|
||||||
| R. Santra & L.S. Cederbaum | Coulombic Energy Transfer and Triple Ionization in Clusters | 2003 | Phys. Rev. Lett. 90, 153401 |
|||
| Abstract: {Using neon and its dimer as a specific example, it is shown that excited Auger decay channels that are electronically stable in the isolated monomer can relax in a cluster by electron emission. The decay mechanism, leading to the formation of a tricationic cluster, is based on an efficient energy-transfer process from the excited, dicationic monomer to a neighbor. The decay is ultrafast and expected to be relevant to numerous physical phenomena involving core holes in clusters and other forms of spatially extended atomic and molecular matter.} | ||||||
BibTeX:
@article{Santra03,
author = {Santra, R. and Cederbaum, L. S.},
title = {{Coulombic Energy Transfer and Triple Ionization in Clusters}},
journal = {Phys. Rev. Lett.},
publisher = {American Physical Society},
year = {2003},
volume = {90},
issue = {15},
pages = {153401},
numpages = {4},
note = {theory},
doi = {https://doi.org/10.1103/PhysRevLett.90.153401}
}
|
||||||
| Ch. Buth, R. Santra & L.S. Cederbaum | Impact of interatomic electronic decay processes on Xe 4d hole decay in the xenon fluorides | 2003 | J. Chem. Phys. 119, 10575 |
|||
| Abstract: {A hole in a 4d orbital of atomic xenon relaxes through Auger decay after a lifetime of 3 fs. Adding electronegative fluorine ligands to form xenon fluoride molecules, results in withdrawal of valence-electron density from Xe. Thus, within the one-center picture of Auger decay, a lowered Xe 4d Auger width would be expected, in contradiction, however, with experiment. Employing extensive ab initio calculations within the framework of many-body Green's functions, we determine all available decay channels in XeFn and characterize these channels by means of a two-hole population analysis. We derive a relation between two-hole population numbers and partial Auger widths. On this basis, interatomic electronic decay processes are demonstrated to be so strong in the xenon fluorides that they overcompensate the reduction in intra-atomic Auger width and lead to the experimentally observed trend. The nature of the relevant processes is discussed. These processes presumably underlie Auger decay in a variety of systems.} | ||||||
BibTeX:
@article{Buth03,
author = {Buth, Ch. and Santra, R. and Cederbaum, L. S.},
title = {{Impact of interatomic electronic decay processes on Xe 4d hole decay in the xenon fluorides}},
journal = {J. Chem. Phys.},
publisher = {AIP},
year = {2003},
volume = {119},
issue = {20},
pages = {10575},
numpages = {10},
note = {theory},
doi = {https://doi.org/10.1063/1.1620502}
}
|
||||||
| S. Scheit, V. Averbukh, H.-D. Meyer, N. Moiseyev, R. Santra, T. Sommerfeld, J. Zobeley & L.S. Cederbaum | On the interatomic Coulombic decay in the Ne dimer | 2004 | J. Chem. Phys. 121, 8393 |
|||
| Abstract: {The interatomic Coulombic decay (ICD) in the Ne dimer is discussed in view of the recent experimental results. The ICD electron spectrum and the kinetic energy release of the Ne+ fragments resulting after Coulomb explosion of Ne22+ are computed and compared to the measured ones. A very good agreement is found, confirming the dynamics predicted for this decay mechanism. The effect of the temperature on the electron spectrum is briefly investigated.} | ||||||
BibTeX:
@article{Scheit04,
author = {Scheit, S. and Averbukh, V. and Meyer, H.-D. and Moiseyev, N. and Santra, R. and Sommerfeld, T. and Zobeley, J. and Cederbaum, L. S.},
title = {{On the interatomic Coulombic decay in the Ne dimer}},
journal = {J. Chem. Phys.},
publisher = {AIP},
year = {2004},
volume = {121},
issue = {17},
pages = {8393},
numpages = {6},
note = {theory},
doi = {https://doi.org/10.1063/1.1794654}
}
|
||||||
| V. Averbukh, I.B. Müller & L.S. Cederbaum | Mechanism of Interatomic Coulombic Decay in Clusters | 2004 | Phys. Rev. Lett. 93, 263002 |
|||
| Abstract: {Interatomic (or intermolecular) Coulombic decay is a general, very efficient mode of decay of inner valence vacancies in clusters. The physically appealing interpretation of such decays as a transfer of a virtual photon between two cluster units rests on the neglect of the orbital overlap between them. We show that even in loosely bound van der Waals clusters the orbital overlap is a crucial factor. At the equilibrium geometry of a cluster, the overlap effect can bring about an enhancement of the decay rate by 2-3 orders of magnitude, making the process dramatically more efficient than implied by the simple estimations.} | ||||||
BibTeX:
@article{Averbukh04,
author = {Averbukh, V. and Müller, I. B. and Cederbaum, L. S.},
title = {{Mechanism of Interatomic Coulombic Decay in Clusters}},
journal = {Phys. Rev. Lett.},
publisher = {American Physical Society},
year = {2004},
volume = {93},
issue = {26},
pages = {263002},
numpages = {4},
note = {theory},
doi = {https://doi.org/10.1103/PhysRevLett.93.263002}
}
|
||||||
| S. Scheit, H.-D. Meyer & L.S. Cederbaum | The interatomic Coulombic decay in Ne2 | 2005 | J. Phys.: Conf. Ser. 4, 277 |
|||
| Abstract: {The Interatomic Coulomb Decay (ICD) is a radiationless decay mechanism occurring via electron emission in inner valence ionized weakly bound clusters. In this article the theoretical description of the ICD in the inner valence ionized Ne dimer is presented, using a time-dependent formalism based on nuclear wave packet propagation. The theoretical predictions are compared with the first experimental results, and a very good agreement is found.} | ||||||
BibTeX:
@proceedings{Scheit05,
author = {Scheit, S. and Meyer, H.-D. and Cederbaum, L. S.},
title = {{The interatomic Coulombic decay in Ne2}},
journal = {J. Phys.: Conf. Ser.},
series= {The 6th International Conference on Dissociative Recombination: (DR2004)},
publisher = {IOP},
year = {2005},
volume = {4},
pages = {277},
numpages = {5},
note = {theory},
doi = {https://doi.org/10.1088/1742-6596/4/1/042}
}
|
||||||
| R. Santra & L.S. Cederbaum | Erratum: Coulombic Energy Transfer and Triple Ionization in Clusters [Phys. Rev. Lett. 90,153401(2003)] [BibTeX] |
2005 | Phys. Rev. Lett. 94, 199901 |
|||
BibTeX:
@article{Santra05,
author = {Santra, R. and Cederbaum, L. S.},
title = {{Erratum: Coulombic Energy Transfer and Triple Ionization in Clusters [Phys. Rev. Lett. 90,153401(2003)]}},
journal = {Phys. Rev. Lett.},
publisher = {American Physical Society},
year = {2005},
volume = {94},
issue = {19},
pages = {199901},
numpages = {1},
note = {theory},
doi = {https://doi.org/10.1103/PhysRevLett.94.199901}
}
|
||||||
| I.B. Müller & L.S. Cederbaum | Electronic decay following ionization of aqueous Li+ microsolvation clusters | 2005 | J. Chem. Phys. 122, 094305 |
|||
| Abstract: {Ionization in the energetical range between 35 eV and 75 eV of aqueous Li+ microsolvation clusters may initialize several different electronic decay processes. Electronic decay following H2O 2s ionization in a cationic cluster is reported. Li ionization probes the efficiency of electron transfer mediated decay (ETMD) processes. We report estimated ETMD lifetimes in the range of 20-100 fs for clusters with one to five water monomers. Furthermore, tertiary electron emission may occur via a combined cascade of electron transfer mediated decay and intermolecular Coulombic decay.} | ||||||
BibTeX:
@article{Mueller05,
author = {Müller, I. B. and Cederbaum, L. S.},
title = {{Electronic decay following ionization of aqueous Li+ microsolvation clusters}},
journal = {J. Chem. Phys.},
publisher = {AIP},
year = {2005},
volume = {122},
issue = {9},
pages = {094305},
numpages = {11},
note = {theory},
doi = {https://doi.org/10.1063/1.1854118}
}
|
||||||
| K. Gokhberg, A.B. Trofimov, T. Sommerfeld & L.S. Cederbaum | Ionization of metal atoms following valence-excitation of neighbouring molecules | 2005 | Europhys. Lett. 72, 228 |
|||
| Abstract: {A new relaxation pathway of optically allowed valence-excitations in molecules bound to metal atoms was investigated. We show that the σnonπ* excitation of HCN in MgnHCN (n=1,2) clusters decays through the emission of an electron from the metallic component. The calculated lifetimes are of the order of 140 fs for MgHCN and 25 fs for Mg2HCN. These short lifetimes suggest that the relaxation mechanism discussed here should dominate for molecules adsorbed on metal clusters or surfaces. We find that at large distances this decay is dominated by energy transfer.} | ||||||
BibTeX:
@article{Gokhberg05,
author = {Gokhberg, K. and Trofimov, A. B. and Sommerfeld, T. and Cederbaum, L. S.},
title = {{Ionization of metal atoms following valence-excitation of neighbouring molecules}},
journal = {Europhys. Lett.},
publisher = {IOP},
year = {2005},
volume = {72},
issue = {2},
pages = {228},
numpages = {7},
note = {theory},
doi = {https://doi.org/10.1209/epl/i2005-10227-7}
}
|
||||||
| M.S. Deleuze, J.-P. Francois & E.S. Kryachko | The Fate of Dicationic States in Molecular Clusters of Benzene and Related Compounds | 2005 | J. Am. Chem. Soc. 127, 16824 |
|||
| Abstract: {Calculations employing density functional theory indicate that, rather than undergoing fragmentation, dicationic clusters of benzene, hexafluorobenzene, and naphthalene produced by sequential one-electron or sudden double-ionization experiments on the neutrals can relax via the formation of inter-ring covalent C-C bonds, along with a series of proton transfers that enable a substantial reduction of inter- and intramolecular Coulomb repulsions. The theoretically predicted chemically bound structures correspond to deep local energy minima on the potential energy surface pertaining to the lowest electronic state of the dications and can therefore be regarded as metastable (kinetically long-lived) species. This discovery invalidates on theoretical grounds the liquid-droplet model of multiply charged clusters and sheds very unexpected light on possible consequences in chemistry of the intermolecular Coulombic decay (ICD) mechanism [Cederbaum, L. S.; et al. Phys. Rev. Lett. 1997, 79, 4778; Jahnke, T.; et al. Phys. Rev. Lett. 2004, 93, 163401] for deep inner-valence ionized states. Propagation of charge rearrangement reactions and proton transfers to several monomers may eventually lead to the formation of rather extended dicationic assemblies.} | ||||||
BibTeX:
@article{Deleuze05,
author = {Deleuze, M. S. and Francois, J.-P. and Kryachko, E. S.},
title = {{The Fate of Dicationic States in Molecular Clusters of Benzene and Related Compounds}},
journal = {J. Am. Chem. Soc.},
publisher = {American Chemical Society},
year = {2005},
volume = {127},
issue = {48},
pages = {16824},
numpages = {11},
note = {theory},
doi = {https://doi.org/10.1021/ja042238j}
}
|
||||||
| V. Averbukh & L.S. Cederbaum | Ab initio calculation of interatomic decay rates by a combination of the Fano ansatz, Green's-function methods, and the Stieltjes imaging technique | 2005 | J. Chem. Phys. 123, 204107 |
|||
| Abstract: {A new computational technique is introduced for the ab initio calculation of the rates of interatomic and intermolecular nonradiative decay processes occurring due to electronic correlation. These recently discovered phenomena are described theoretically using the configuration-interaction formalism first introduced by Fano [Phys. Rev. 124, 1866 (1961)] and later adapted to an Auger decay by Howat et al. [J. Phys. B 11, 1575 (1978)]. The boundlike and the continuumlike components of the wave function of the decaying state are constructed using a Green's-function method known as algebraic diagrammatic construction. A combination of atomic and distributed Gaussian basis sets is shown to provide an adequate description of both boundlike and continuumlike wave-function components. The problem of the normalization of the continuum (final state) wave function is addressed using the Stieltjes imaging technique. The new method is applied to the calculation of the rates of interatomic decay in alkaline-earth-rare-gas clusters. The obtained results help to verify our earlier conclusions [Phys. Rev. Lett. 93, 263002 (2004)] regarding the validity of the virtual-photon transfer model for the interatomic Coulombic decay. In addition, we demonstrate that the process of electron-transfer-mediated decay is responsible for the finite lifetimes of the outer valence vacancies in alkaline-earth-rare-gas clusters.} | ||||||
BibTeX:
@article{Averbukh05,
author = {Averbukh, V. and Cederbaum, L. S.},
title = {{Ab initio calculation of interatomic decay rates by a combination of the Fano ansatz, Green's-function methods, and the Stieltjes imaging technique}},
journal = {J. Chem. Phys.},
publisher = {AIP},
year = {2005},
volume = {123},
issue = {20},
pages = {204107},
numpages = {13},
note = {theory},
doi = {https://doi.org/10.1063/1.2126976}
}
|
||||||
| S. Scheit, V. Averbukh, H.-D. Meyer, J. Zobeley & L.S. Cederbaum | Interatomic Coulombic decay in a heteroatomic rare gas cluster | 2006 | J. Chem. Phys. 124, 154305 |
|||
| Abstract: {Interatomic decay in a heteroatomic rare gas cluster (NeAr) is studied in detail using ab initio electronic structure description and nuclear dynamics simulations. Decay widths of all possible interatomic decay processes are calculated by the recently developed method based on Green's function formalism. Kinetic energy spectra of the electrons emitted in the course of interatomic Coulombic decay (ICD) are simulated for a series of initial vibrational states of the neutral cluster. The effect of the nuclear dynamics on the ICD electron spectra is discussed.} | ||||||
BibTeX:
@article{Scheit06,
author = {Scheit, S. and Averbukh, V. and Meyer, H.-D. and Zobeley, J. and Cederbaum, L. S.},
title = {{Interatomic Coulombic decay in a heteroatomic rare gas cluster}},
journal = {J. Chem. Phys.},
publisher = {AIP},
year = {2006},
volume = {124},
issue = {15},
pages = {154305},
numpages = {8},
note = {theory},
doi = {https://doi.org/10.1063/1.2185637}
}
|
||||||
| M. Pernpointner, S. Knecht & L.S. Cederbaum | Ionization spectra and electronic decay in small iodide clusters: Fully relativistic results | 2006 | J. Chem. Phys. 125, 034309 |
|||
| Abstract: {Singly ionized systems in high-lying energetic final states can stabilize themselves via various electronic decay mechanisms. With increasing system size interatomic and intermolecular processes dominate over intra-atomic (Auger) decay channels. For the small (HI)2 and (LiI)2 clusters fully relativistic ionization spectra are calculated and the subsequent electronic decay of the cations is investigated. Due to the presence of the iodine atom a fully relativistic description is mandatory and was performed by the algebraic diagrammatic construction technique in its four-component form. The lifetimes of the singly ionized final states are estimated by the application of Weisskopf-Wigner [Z. Phys. 63, 54 (1930)] theory.} | ||||||
BibTeX:
@article{Pernpointner06,
author = {Pernpointner, M. and Knecht, S. and Cederbaum, L. S.},
title = {{Ionization spectra and electronic decay in small iodide clusters: Fully relativistic results}},
journal = {J. Chem. Phys.},
publisher = {AIP},
year = {2006},
volume = {125},
issue = {3},
pages = {034309},
numpages = {8},
note = {theory},
doi = {https://doi.org/10.1063/1.2222363}
}
|
||||||
| I.B. Müller & L.S. Cederbaum | Ionization and double ionization of small water clusters | 2006 | J. Chem. Phys. 125, 204305 |
|||
| Abstract: {The valence ionization and double ionization spectra of the water molecule, of the water dimer, and the cyclic water clusters (H2O)3 and (H2O)4 are calculated by ab initio Green's function methods and discussed in some detail. Particular attention is paid to the analysis of the development of the spectra with increasing cluster size. Electronic decay following inner valence ionization is addressed and a crude estimate for the kinetic energy spectrum of the secondary electrons is given for the clusters.} | ||||||
BibTeX:
@article{Mueller06,
author = {Müller, I. B. and Cederbaum, L. S.},
title = {{Ionization and double ionization of small water clusters}},
journal = {J. Chem. Phys.},
publisher = {AIP},
year = {2006},
volume = {125},
issue = {20},
pages = {204305},
numpages = {12},
note = {theory},
doi = {https://doi.org/10.1063/1.2357921}
}
|
||||||
| K. Gokhberg, V. Averbukh & L.S. Cederbaum | Interatomic decay of inner-valence-excited states in clusters | 2006 | J. Chem. Phys. 124, 144315 |
|||
| Abstract: {In an isolated atom, excitation of an inner valence electron above the outer valence subshell leads to creation of an autoionizing state. Recently, it has been demonstrated experimentally that in a cluster, the inner-valence-excited states can decay also by an interatomic mechanism which has been called resonant interatomic Coulombic decay (RICD). Here we show that RICD is indeed the leading but not the only possible interatomic decay mode of the inner-valence excitations in clusters. Using Ne(2s→3p) excitation in MgNe cluster as an example, we explore the possible decay mechanisms and draw conclusions on their relative importance and on the nature of the corresponding decay products.} | ||||||
BibTeX:
@article{Gokhberg06,
author = {Gokhberg, K. and Averbukh, V. and Cederbaum, L. S.},
title = {{Interatomic decay of inner-valence-excited states in clusters}},
journal = {J. Chem. Phys.},
publisher = {AIP},
year = {2006},
volume = {124},
issue = {14},
pages = {144315},
numpages = {9},
note = {theory},
doi = {https://doi.org/10.1063/1.2187472}
}
|
||||||
| V. Averbukh & L.S. Cederbaum | Calculation of interatomic decay widths of vacancy states delocalized due to inversion symmetry | 2006 | J. Chem. Phys. 125, 094107 |
|||
| Abstract: {In a recent publication [J. Chem. Phys. 123, 204107 (2005)], we have introduced a new ab initio approach for the calculation of the widths of interatomic electronic decay of inner-shell vacancies in clusters. The new technique is based on the configuration interaction formalism first introduced for the description of resonance states by Fano [Phys. Rev. 124, 1866 (1961)] and on a Green function method for the description of the many-electron states involved in the electronic decay. Central to the new method is the selection of the physical excitation operators for the construction of the initial and final states of the interatomic decay. The previously described selection procedure has been formulated for localized vacancy states and runs into difficulties when applied to the decay of vacancy states delocalized due to inversion symmetry, e.g., (2s-1) 2Σg,u+ states of Ne2+. Here we present a modified computational scheme suitable for interatomic decay of the energy-split gerade and ungerade states and apply it to the interatomic Coulombic decay in two homonuclear diatomic clusters: Ne2 and Ca2} | ||||||
BibTeX:
@article{Averbukh06_1,
author = {Averbukh, V. and Cederbaum, L. S.},
title = {{Calculation of interatomic decay widths of vacancy states delocalized due to inversion symmetry}},
journal = {J. Chem. Phys.},
publisher = {AIP},
year = {2006},
volume = {125},
issue = {9},
pages = {094107},
numpages = {7},
note = {theory},
doi = {https://doi.org/10.1063/1.2244567}
}
|
||||||
| V. Averbukh & L.S. Cederbaum | Interatomic Electronic Decay in Endohedral Fullerenes | 2006 | Phys. Rev. Lett. 96, 053401 |
|||
| Abstract: {Ionization of an atom X in an endohedral fullerene complex X@Cn can lead to a wealth of nonradiative decay processes. These interatomic processes occur due to the correlation existing between the atomic and the fullerene electrons and do not take place in the free species X. Considering Ne@C60 as an example, we calculate the rates of the interatomic decay processes and show that the interatomic decay in Ne@C60 is ultrafast. Moreover, our analysis suggests that interatomic decay in an endohedral fullerene does not necessarily lead to the destruction of the complex.} | ||||||
BibTeX:
@article{Averbukh06_2,
author = {Averbukh, V. and Cederbaum, L. S.},
title = {{Interatomic Electronic Decay in Endohedral Fullerenes}},
journal = {Phys. Rev. Lett.},
publisher = {American Physical Society},
year = {2006},
volume = {96},
issue = {5},
pages = {053401},
numpages = {4},
note = {theory},
doi = {https://doi.org/10.1103/PhysRevLett.96.053401}
}
|
||||||
| N. Vaval & L.S. Cederbaum | Ab initio lifetimes in the interatomic Coulombic decay of neon clusters computed with propagators | 2007 | J. Chem. Phys. 126, 164110 |
|||
| Abstract: {Interatomic Coulombic decay (ICD) is a radiationless decay mechanism occurring via electron emission in an inner-valence ionized weakly bound cluster. The ICD has been studied for the neon clusters Nen (n=2,...,5). The decay widths of the neon clusters are calculated using ab initio Green's function method. The non-Dyson version of Green's function is employed. This propagator is analytically continued into the complex energy plane with the aid of a complex absorbing potential, and the decaying states are found as resonance states in this plane.} | ||||||
BibTeX:
@article{Vaval07,
author = {Vaval, N. and Cederbaum, L. S.},
title = {{Ab initio lifetimes in the interatomic Coulombic decay of neon clusters computed with propagators}},
journal = {J. Chem. Phys.},
publisher = {AIP},
year = {2007},
volume = {126},
issue = {16},
pages = {164110},
numpages = {6},
note = {theory},
doi = {https://doi.org/10.1063/1.2723117}
}
|
||||||
| M. Pernpointner & L.S. Cederbaum | PtF62- dianion and its detachment spectrum: A fully relativistic study | 2007 | J. Chem. Phys. 126, 144310 |
|||
| Abstract: {In this work we calculate the photoelectron spectrum of the PtF62- dianion by application of the third-order Dirac-Hartree-Fock one-particle propagator technique. Relativistic effects and electron correlation are hereby treated on a consistent theoretical basis which is mandatory for systems containing heavy elements. A PtF62- gas phase photoelectron spectrum is not yet available and our calculations therefore have predictive character. As it is characteristic for dianionic systems a strong dependence on basis set size and molecular geometry is observed. In contrast to the already calculated PtCl62- photoelectron spectrum no valence orbital inversion due to strong interplay of spin-orbit coupling and electron correlation is observed. Furthermore an unusually strong spin-orbit splitting was found for the σ-type subvalence 1t1u molecular spinor despite its very small platinum p population. The double ionization threshold is strongly lowered by relativistic effects now enabling an interatomic Coulombic decay process after ionization from the σ-bonding orbitals. The results stress the importance of spin-orbit coupling for the understanding of the spectral structure which cannot be reproduced by a scalar-relativistic treatment only.} | ||||||
BibTeX:
@article{Pernpointner07,
author = {Pernpointner, M. and Cederbaum, L. S.},
title = {{PtF62- dianion and its detachment spectrum: A fully relativistic study}},
journal = {J. Chem. Phys.},
publisher = {AIP},
year = {2007},
volume = {126},
issue = {14},
pages = {144310},
numpages = {7},
note = {theory},
doi = {https://doi.org/10.1063/1.2721531}
}
|
||||||
| A.I. Kuleff & L.S. Cederbaum | Tracing Ultrafast Interatomic Electronic Decay Processes in Real Time and Space | 2007 | Phys. Rev. Lett. 98, 083201 |
|||
| Abstract: {Advances in laser pump-probe techniques open the door for observations in real time of ultrafast electronic processes. Particularly attractive is the visualization of interatomic processes where one can follow the energy transfer from one atom to another. The interatomic Coulombic decay (ICD) provides such a process which is abundant in nature. A wave packet propagation method now enables us to trace fully ab initio the electron dynamics of the process in real time and space, taking into account all electrons of the system and their correlations. The evolution of the electronic cloud during the ICD process in NeAr following Ne2s ionization is computed and analyzed. The process takes place on a femtosecond time scale, and a surprisingly strong response is found already in the attosecond regime.} | ||||||
BibTeX:
@article{Kuleff07,
author = {Kuleff, A. I. and Cederbaum, L. S.},
title = {{Tracing Ultrafast Interatomic Electronic Decay Processes in Real Time and Space}},
journal = {Phys. Rev. Lett.},
publisher = {American Physical Society},
year = {2007},
volume = {98},
issue = {8},
pages = {083201},
numpages = {4},
note = {theory},
doi = {https://doi.org/10.1103/PhysRevLett.98.083201}
}
|
||||||
| N.V. Kryzhevoi, V. Averbukh & L.S. Cederbaum | High activity of helium droplets following ionization of systems inside those droplets | 2007 | Phys. Rev. B 76, 094513 |
|||
| Abstract: {Relaxation processes following inner-valence ionization of a system can be modified dramatically by embedding this system in a suitable environment. Surprisingly, such an environment can even be composed of helium atoms, the most inert species available. As demonstrated by the examples of Ne and Ca atoms embedded in He droplets, a fast relaxation process [interatomic Coulombic decay (ICD)] takes place merely due to the presence of the He surroundings. We have computed ICD widths for both 4HeN and 3HeN droplets doped with Ne and Ca and discuss the findings in some detail. In the case of Ne, ICD is by far the dominating relaxation pathway. In Ca, atomic Auger decay is also possible but ICD becomes a competitive relaxation pathway in the droplets.} | ||||||
BibTeX:
@article{Kryzhevoi07,
author = {Kryzhevoi, N. V. and Averbukh, V. and Cederbaum, L. S.},
title = {{High activity of helium droplets following ionization of systems inside those droplets}},
journal = {Phys. Rev. B},
publisher = {American Physical Society},
year = {2007},
volume = {76},
issue = {9},
pages = {094513},
numpages = {5},
note = {theory},
doi = {https://doi.org/10.1103/PhysRevB.76.094513}
}
|
||||||
| V. Averbukh & L.S. Cederbaum | Interatomic (Intermolecular) Decay Processes in Clusters: Current Status and Outlook | 2007 | AIP Conf. Proc. 963, 39 |
|||
| Abstract: {Since their theoretical prediction a decade ago, interatomic (intermolecular) Coulombic decay (ICD) and related processes have been in the focus of intensive theoretical and experimental research. The spectacular progress in this direction has been stimulated both by the fundamental importance of the new electronic decay phenomena and by the exciting possibility of their practical application, for example in spectroscopy. We review the current status of the research of interatomic (intermolecular) decay phenomena in clusters and discuss some perspectives of this new field.} | ||||||
BibTeX:
@proceedings{Averbukh07,
author = {Averbukh, V. and Cederbaum, L. S.},
title = {{Interatomic (Intermolecular) Decay Processes in Clusters: Current Status and Outlook}},
journal = {AIP Conf. Proc.},
series= {the International Conference on Computational Methods in Science and Engineering (ICCMSE 2007)},
publisher = {AIP},
year = {2007},
volume = {963},
issue = {1},
pages = {39},
numpages = {8},
note = {theory},
doi = {https://doi.org/10.1063/1.2827022}
}
|
||||||
| S.D. Stoychev, A.I. Kuleff, F. Tarantelli & L.S. Cederbaum | On the doubly ionized states of Ar2 and their intra- and interatomic decay to Ar23+ | 2008 | J. Chem. Phys. 128, 014307 |
|||
| Abstract: {Potential energy curves of the Auger state Ar+(2p-1)-Ar, the different one- and two-site dicationic states Ar2++ (with energies in the range of 32-77 eV), and the lowest two-site tricationic states Ar++-Ar+ (with energies in the range of 64-76 eV) computed using elaborated ab initio methods are reported. The accessible relaxation channels of the electronic states of Ar++-Ar populated by Auger decay are studied. In particular, we study in detail the interatomic Coulombic decay following the population of one-site satellite states of Ar++(3s-13p-1)-Ar recently observed experimentally. Other relaxation pathways of Ar++-Ar, including radiative charge transfer, nuclear dynamics through curve crossing, and intra-atomic decay processes are also investigated.} | ||||||
BibTeX:
@article{Stoychev08_1,
author = {Stoychev, S. D. and Kuleff, A. I. and Tarantelli, F. and Cederbaum, L. S.},
title = {{On the doubly ionized states of Ar2 and their intra- and interatomic decay to Ar23+}},
journal = {J. Chem. Phys.},
publisher = {AIP},
year = {2008},
volume = {128},
issue = {1},
pages = {014307},
numpages = {10},
note = {theory},
doi = {https://doi.org/10.1063/1.2814241}
}
|
||||||
| S.D. Stoychev, A.I. Kuleff, F. Tarantelli & L.S. Cederbaum | On the interatomic electronic processes following Auger decay in neon dimer | 2008 | J. Chem. Phys. 129, 074307 |
|||
| Abstract: {The accessible relaxation channels of the electronic states of Ne++-Ne and Ne3+-Ne populated by KLL Auger decay are studied. In particular, we address the “direct” and “exchange” interatomic Coulombic decays (ICDs) and the electron-transfer-mediated decay following the population of one-site states Ne++(2s-2)-Ne and Ne++(2s-12p-1 1P)-Ne. Radiative charge transfer of the low lying Ne++(2p-2)-Ne states, three-electron ICD process from the Ne++(2s-2)-Ne states, as well as charge transfer at the points of curve crossing of the lowest in energy Ne3+(2p-3)-Ne states are also discussed. To carry out the present study, we have calculated the potential energy curves (from 1.75 to 5.00 Å) of the ground state Ne2, the core ionized state Ne+(1s-1)-Ne, and the dicationic and tricationic states with energies in the range of 45-140 eV using accurate ab initio methods and basis sets. Apart from being of interest by themselves, the results obtained may be helpful in interpreting the recent measurements of interatomic electronic processes following Auger decay in neon dimer [K. Kreidi et al., J. Phys. B 41, 101002 (2008)].} | ||||||
BibTeX:
@article{Stoychev08_2,
author = {Stoychev, S. D. and Kuleff, A. I. and Tarantelli, F. and Cederbaum, L. S.},
title = {{On the interatomic electronic processes following Auger decay in neon dimer}},
journal = {J. Chem. Phys.},
publisher = {AIP},
year = {2008},
volume = {129},
issue = {7},
pages = {074307},
numpages = {11},
note = {theory},
doi = {https://doi.org/10.1063/1.2960593}
}
|
||||||
| M. Pernpointner, N.V. Kryzhevoi & S. Urbaczek | Possible electronic decay channels in the ionization spectra of small clusters composed of Ar and Kr: A four-component relativistic treatment | 2008 | J. Chem. Phys. 129, 024304 |
|||
| Abstract: {In this work single and double ionization spectra of the homo- and heteronuclear argon/krypton dimers and trimers are calculated by means of propagator methods where a four-component implementation was employed for the single ionizations. Scalar relativistic effects play only a minor role for the outer valence spectral structure, whereas spin-orbit coupling and electron correlation have to be treated adequately in order to reproduce the features correctly. Nonradiative decay mechanisms of subvalence vacancies in the argon and krypton dimers and trimers are discussed both for the interatomic Coulombic decay and the electron transfer mediated decay (ETMD). In the heteronuclear triatomic system which serves as a model for larger clusters, a possible ETMD process of the Ar 3s vacancy is found for the linear arrangement of the atoms. In the bent configuration the ETMD channel is closed.} | ||||||
BibTeX:
@article{Pernpointner08,
author = {Pernpointner, M. and Kryzhevoi, N. V. and Urbaczek, S.},
title = {{Possible electronic decay channels in the ionization spectra of small clusters composed of Ar and Kr: A four-component relativistic treatment}},
journal = {J. Chem. Phys.},
publisher = {AIP},
year = {2008},
volume = {129},
issue = {2},
pages = {024304},
numpages = {8},
note = {theory},
doi = {https://doi.org/10.1063/1.2952272}
}
|
||||||
| P. Kolorenč, V. Averbukh, K. Gokhberg & L.S. Cederbaum | Ab initio calculation of interatomic decay rates of excited doubly ionized states in clusters | 2008 | J. Chem. Phys. 129, 244102 |
|||
| Abstract: {Recently, a computational technique for ab initio calculation of the interatomic and intermolecular nonradiative decay processes has been developed [V. Averbukh and L. S. Cederbaum, J. Chem. Phys. 123, 204107 (2005)]. It combines the Fano formalism with the Green's function method known as the algebraic diagrammatic construction. The problem of normalization of continuum wave functions stemming from the use of the Gaussian basis sets is solved by using the Stieltjes imaging technique. In the present paper, the methodology is extended in order to describe the interatomic decay of excited doubly ionized states of clusters. The new computational scheme is applied to compute the interatomic decay rates of doubly ionized states formed by Auger relaxation of core vacancies in NeAr and MgNe van der Waals clusters.} | ||||||
BibTeX:
@article{Kolorenc08,
author = {Kolorenč, P. and Averbukh, V. and Gokhberg, K. and Cederbaum, L. S.},
title = {{Ab initio calculation of interatomic decay rates of excited doubly ionized states in clusters}},
journal = {J. Chem. Phys.},
publisher = {AIP},
year = {2008},
volume = {129},
issue = {24},
pages = {244102},
numpages = {12},
note = {theory},
doi = {https://doi.org/10.1063/1.3043437}
}
|
||||||
| A.M. Dias | Study of electronic transitions by interatomic Coulombic decay in neon dimer | 2008 | Physica B: Condens. Matter 403, 3490 |
|||
| Abstract: { The energies involved in the interatomic Coulombic decay (ICD) in neon dimer are discussed through the molecular orbital formalism. This recent type of transition, emerges from the ionization of inner layers associated with weakly bound molecular complexes or clusters, also known as van der Waals systems. First, we will describe the ICD process, and then we will demonstrate how a formal relation among the energies can be obtained in the process. We have carried out an ab initio calculation to measure the involved electronic energy states, and to predict the final energy process, which corresponds to the energy of the fragment pair Ne+(2p-1), called kinetic energy release (KER), and the energy of the emitted ICD electron. The values obtained have been compared with those of other theoretical results and the first experimental data reported in the literature.} | ||||||
BibTeX:
@article{Dias08,
author = {Dias, A. M.},
title = {{Study of electronic transitions by interatomic Coulombic decay in neon dimer}},
journal = {Physica B: Condens. Matter},
publisher = {Elsevier},
year = {2008},
volume = {403},
issue = {19--20},
pages = {3490},
numpages = {5},
note = {theory},
doi = {https://doi.org/10.1016/j.physb.2008.05.014}
}
|
||||||
| Ph.V. Demekhin, S. Scheit, S.D. Stoychev & L.S. Cederbaum | Dynamics of interatomic Coulombic decay in a Ne dimer following the K-L1L2,3(1P) Auger transition in the Ne atom | 2008 | Phys. Rev. A 78, 043421 |
|||
| Abstract: {The interatomic Coulombic decay (ICD) following K-shell ionization of the Ne dimer and subsequent one-site atomic Auger decay of the Ne2+(1s-1) states is studied theoretically. In particular we consider electronic decay of the Ne2+ (2s-12p-1 1P)Ne weakly bound doubly ionized states into the manifold of the Ne2+(2p-2 1D) - Ne+(2p-1) repulsive triply ionized ones. The total and partial ICD electron spectra are computed within the framework of the time-dependent theory of wave packet propagation. Thereby, we investigate the impact of nuclear dynamics accompanying the electronic decay on the computed spectra in some detail. The computed total ICD electron spectrum is found to be in very good agreement with the recently measured one.} | ||||||
BibTeX:
@article{Demekhin08,
author = {Demekhin, Ph. V. and Scheit, S. and Stoychev, S. D. and Cederbaum, L. S.},
title = {{Dynamics of interatomic Coulombic decay in a Ne dimer following the K-L1L2,3(1P) Auger transition in the Ne atom}},
journal = {Phys. Rev. A},
publisher = {American Physical Society},
year = {2008},
volume = {78},
issue = {4},
pages = {043421},
numpages = {8},
note = {theory},
doi = {https://doi.org/10.1103/PhysRevA.78.043421}
}
|
||||||
| S. Kopelke, K. Gokhberg, L.S. Cederbaum & V. Averbukh | Calculation of resonant interatomic Coulombic decay widths of inner-valence-excited states delocalized due to inversion symmetry | 2009 | J. Chem. Phys. 130, 144103 |
|||
| Abstract: {Inner-valence-excited states of clusters can decay by electron emission via several of mechanisms, the leading ones being intra atomic autoionization and resonant interatomic Coulombic decay. Recently, we have derived the Wigner-Weisskopf theory for the calculation of the decay widths of the inner valence excitations [J. Chem. Phys. 124, 144315 (2006)]. While the new method has been successful in producing the decay rates of heteronuclear diatomic clusters, it cannot be applied to systems possessing inversion symmetry, e.g., to homonuclear diatoms, due to delocalization of the molecular orbitals involved in the decay processes. In the present work, we show that the Wigner-Weisskopf theory of the decay of inner-valence-excited states can be generalized to systems with inversion symmetry using a technique of adapted final states [J. Chem. Phys. 125, 094107 (2006)]. The same technique can be employed when going beyond the Wigner-Weisskopf theory. We consider the experimentally relevant case of competing resonant interatomic Coulombic decay and autoionization in neon dimer and calculate the rates of these processes for a series of inner-valence-excited states which has been measured by Aoto et al. [Phys. Rev. Lett. 97, 243401 (2006)].} | ||||||
BibTeX:
@article{Kopelke09,
author = {Kopelke, S. and Gokhberg, K. and Cederbaum, L. S. and Averbukh, V.},
title = {{Calculation of resonant interatomic Coulombic decay widths of inner-valence-excited states delocalized due to inversion symmetry}},
journal = {J. Chem. Phys.},
publisher = {AIP},
year = {2009},
volume = {130},
issue = {14},
pages = {144103},
numpages = {9},
note = {theory},
doi = {https://doi.org/10.1063/1.3109988}
}
|
||||||
| K. Gokhberg & L.S. Cederbaum | Environment assisted electron capture | 2009 | J. Phys. B: At. Mol. Opt. Phys. 42, 231001 |
|||
| Abstract: {Electron capture by isolated atoms and ions proceeds by photorecombination. In this process, a species captures a free electron by emitting a photon which carries away the excess energy. It is shown here that in the presence of an environment a competing non-radiative electron capture process can take place due to long range electron correlation. In this interatomic (intermolecular) process the excess energy is transferred to neighbouring species. The asymptotic expression for the cross section of this process is derived. We demonstrate by explicit examples that under realizable conditions, the cross section of this interatomic process can clearly dominate that of photorecombination.} | ||||||
BibTeX:
@article{Gokhberg09,
author = {Gokhberg, K. and Cederbaum, L. S.},
title = {{Environment assisted electron capture}},
journal = {J. Phys. B: At. Mol. Opt. Phys.},
publisher = {IOP},
year = {2009},
volume = {42},
issue = {23},
pages = {231001},
numpages = {4},
note = {theory},
doi = {https://doi.org/10.1088/0953-4075/42/23/231001}
}
|
||||||
| A.M. Dias | Interatomic Coulombic decay: a short review | 2009 | Brazil. J. Phys. 39, 523 |
|||
| Abstract: {The transition process of the interatomic Coulombic decay (ICD), is an electronic radiationless transition process, driving molecular complexes or clusters to a doubly ionized final state. This process differs from the Auger effect, because it takes place from a neutral monomer after the absorption of a released amount energy of the neighboring monomer in the weakly bound molecule. This process has been theoretically studied and the most recent experimental evidence was observed with neon dimer. This work presents a description of the process and a detailed revision of the derivation for the distribution kinetic energy equation to the emitted electrons by ICD decay, with a small variation in the wave packet form of the transition for the final states , with non-Hermitian time-dependent theory.} | ||||||
BibTeX:
@article{Dias09,
author = {Dias, A. M.},
title = {{Interatomic Coulombic decay: a short review}},
journal = {Brazil. J. Phys.},
year = {2009},
volume = {39},
issue = {3},
pages = {523},
numpages = {2},
note = {theory},
doi = {https://doi.org/10.1590/S0103-97332009000500002}
}
|
||||||
| Ph.V. Demekhin, S. Scheit & L.S. Cederbaum | Recoil by Auger electrons: Theory and application | 2009 | J. Chem. Phys. 131, 164301 |
|||
| Abstract: {General equations accounting for the molecular dynamics induced by the recoil of a fast Auger electron are presented. The implications of the degree of localization of the molecular orbitals of diatomic molecules involved in the Auger decay are analyzed. It is shown that the direct and exchange terms of the Auger transition matrix element may give rise to opposite signs and hence to opposite directions of the recoil momenta transferred to the nuclear vibrational motion. Consequently, these terms have a different impact on the recoil-induced nuclear dynamics in the final Auger decay state. The developed theory is applied to study the influence of the recoil on the interatomic Coulombic decay (ICD) following the K-LL Auger decay of the Ne dimer. Our calculations illustrate a significant effect of the recoil of nuclei on the computed wave packets propagating on the potential energy curve populated by the Auger decay. The corresponding final states of the Auger process decay further by ICD. We show that the recoil momentum imparted onto the nuclei modifies the computed ICD spectra considerably.} | ||||||
BibTeX:
@article{Demekhin09_2,
author = {Demekhin, Ph. V. and Scheit, S. and Cederbaum, L. S.},
title = {{Recoil by Auger electrons: Theory and application}},
journal = {J. Chem. Phys.},
publisher = {AIP},
year = {2009},
volume = {131},
issue = {16},
pages = {164301},
numpages = {13},
note = {theory},
doi = {https://doi.org/10.1063/1.3250348}
}
|
||||||
| Ph.V. Demekhin, Y.-C. Chiang, S.D. Stoychev, P. Kolorenč, S. Scheit, A.I. Kuleff, F. Tarantelli & L.S. Cederbaum | Interatomic Coulombic decay and its dynamics in NeAr following K-LL Auger transition in the Ne atom | 2009 | J. Chem. Phys. 131, 104303 |
|||
| Abstract: {We analyze in detail the accessible relaxation pathways via electron emission of the Ne2+Ar states populated via the K-LL Auger decay of Ne+(1s-1)Ar. In particular, we concentrate on the “direct” interatomic Coulombic decay (ICD) of the Ne2+(2s-12p-1)Ar weakly bound doubly ionized states into the manifold of the Ne2+(2p-2)-Ar+(3p-1) repulsive triply ionized ones. To carry out the present study the potential energy curves of the NeAr ground state, the core ionized state Ne+(1s-1)Ar, the relevant dicationic and tricationic states, and the corresponding ICD transition rates have been computed using accurate ab initio methods and basis sets. The total and partial ICD electron spectra are computed within the framework of the time-dependent theory of wave packet propagation. Thereby, the impact of nuclear dynamics accompanying the electronic decay on the computed ICD-electron spectra is investigated in detail. } | ||||||
BibTeX:
@article{Demekhin09_1,
author = {Demekhin, Ph. V. and Chiang, Y.-C. and Stoychev, S. D. and Kolorenč, P. and Scheit, S. and Kuleff, A. I. and Tarantelli, F. and Cederbaum, L. S.},
title = {{Interatomic Coulombic decay and its dynamics in NeAr following K-LL Auger transition in the Ne atom}},
journal = {J. Chem. Phys.},
publisher = {AIP},
year = {2009},
volume = {131},
issue = {10},
pages = {104303},
numpages = {11},
note = {theory},
doi = {https://doi.org/10.1063/1.3211114}
}
|
||||||
| V. Averbukh, P. Kolorenč, K. Gokhberg & L.S. Cederbaum | Quantum Chemical Approach to Interatomic Decay Rates in Clusters | 2009 | Advances in the Theory of Atomic and Molecular Systems 20, 155 |
|||
| Abstract: {Since their theoretical prediction in 1997, interatomic (intermolecular) Coulombic decay (ICD) and related processes have been in the focus of intensive theoretical and experimental research. The spectacular progress in this direction has been stimulated both by the fundamental importance of the discovered electronic decay phenomena and by the exciting possibility of their practical application, for example, in spectroscopy of interfaces. Interatomic decay phenomena take place in inner-shell-ionized clusters due to electronic correlation between two or more cluster constituents. These processes lead to the decay of inner-shell vacancies by electron emission and often also to the disintegration of the resulting multiple ionized cluster. The primary objective of the theory is, thus, to predict the kinetic energy spectra of the emitted electrons and of the cluster fragments. These spectra are determined by an interplay between the electronic decay process and the nucleardynamics. Key to the reliable prediction of the observable quantities is the knowledge of the time scale of the interatomic decay. Here we review the recent progress in the development of ab initio quantum chemical methods for the calculation of interatomic decay rates in excited, singly ionized, and doubly ionized systems as well as some of their applications, e.g.,~to rare gas systems and to endohedral fullerenes.} | ||||||
BibTeX:
@inbook{Averbukh09_2,
author = {Averbukh, V. and Kolorenč, P. and Gokhberg, K. and Cederbaum, L. S.},
title = {{Quantum Chemical Approach to Interatomic Decay Rates in Clusters}},
journal = {Advances in the Theory of Atomic and Molecular Systems},
publisher = {Springer},
year = {2009},
volume = {20},
pages = {155},
numpages = {26},
note = {theory},
doi = {https://doi.org/10.1007/978-90-481-2985-0_8}
}
|
||||||
| V. Averbukh & P. Kolorenč | Collective Interatomic Decay of Multiple Vacancies in Clusters | 2009 | Phys. Rev. Lett. 103, 183001 |
|||
| Abstract: {We predict that inner-shell ionization of more than one atom (or molecule) in a cluster, e.g., by intense free-electron laser radiation, can lead to an interatomic decay process in which the formed vacancy states decay simultaneously, while a neighboring neutral species is ionized. This collective decay phenomenon can be regarded as a transfer of two or more virtual photons from the ionized cluster units to a neutral one. Simulations of collective decay in (4s-1,4s-1) (Kr+)2Ar show that the two-virtual-photon process can be competitive with the dissociative nuclear dynamics of the doubly ionized cluster. Generality of the collective interatomic decay is discussed.} | ||||||
BibTeX:
@article{Averbukh09_1,
author = {Averbukh, V. and Kolorenč, P.},
title = {{Collective Interatomic Decay of Multiple Vacancies in Clusters}},
journal = {Phys. Rev. Lett.},
publisher = {American Physical Society},
year = {2009},
volume = {103},
issue = {18},
pages = {183001},
numpages = {4},
note = {theory},
doi = {https://doi.org/10.1103/PhysRevLett.103.183001}
}
|
||||||
| T. Amthor, J. Denskat, C. Giese, N.N. Bezuglov, A. Ekers, L.S. Cederbaum & M. Weidemüller | Autoionization of an ultracold Rydberg gas through resonant dipole coupling | 2009 | Eur. Phys. J. D 53, 329 |
|||
| Abstract: {We investigate a possible mechanism for the autoionization of ultracold Rydberg gases, based on the resonant coupling of Rydberg pair states to the ionization continuum. Unlike an atomic collision where the wave functions begin to overlap, the mechanism considered here involves only the long-range dipole interaction and is in principle possible in a static system. It is related to the process of intermolecular Coulombic decay (ICD). In addition, we include the interaction-induced motion of the atoms and the effect of multi-particle systems in this work. We find that the probability for this ionization mechanism can be increased in many-particle systems featuring attractive or repulsive van der Waals interactions. However, the rates for ionization through resonant dipole coupling are very low. It is thus unlikely that this process contributes to the autoionization of Rydberg gases in the form presented here, but it may still act as a trigger for secondary ionization processes. As our picture involves only binary interactions, it remains to be investigated if collective effects of an ensemble of atoms can significantly influence the ionization probability. Nevertheless our calculations may serve as a starting point for the investigation of more complex systems, such as the coupling of many pair states proposed in [P.J. Tanner et al., Phys. Rev. Lett. 100, 043002 (2008)].} | ||||||
BibTeX:
@article{Amthor09,
author = {Amthor, T. and Denskat, J. and Giese, C. and Bezuglov, N. N. and Ekers, A. and Cederbaum, L. S. and Weidemüller, M.},
title = {{Autoionization of an ultracold Rydberg gas through resonant dipole coupling}},
journal = {Eur. Phys. J. D},
publisher = {Springer},
year = {2009},
volume = {53},
issue = {3},
pages = {329},
numpages = {7},
note = {theory},
doi = {https://doi.org/10.1140/epjd/e2009-00119-4}
}
|
||||||
| A.B. Voitkiv & B. Najjari | Two-center dielectronic recombination and resonant photoionization | 2010 | Phys. Rev. A 82, 052708 |
|||
| Abstract: {We consider radiative recombination and photoionization in an atomic system, which consists of two subsystems, A and B. These subsystems are well separated in space and it is supposed that A has a lower ionization potential. In such a case photoionization of A and recombination of an incident electron with A+ can be strongly influenced, via two-center electron-electron correlations, by resonant electron dipole transitions induced in B. A theoretical description of these two-center resonant dielectronic processes is presented.} | ||||||
BibTeX:
@article{Voitkiv10,
author = {Voitkiv, A. B. and Najjari, B.},
title = {{Two-center dielectronic recombination and resonant photoionization}},
journal = {Phys. Rev. A},
publisher = {American Physical Society},
year = {2010},
volume = {82},
issue = {5},
pages = {052708},
numpages = {9},
note = {theory},
doi = {https://doi.org/10.1103/PhysRevA.82.052708}
}
|
||||||
| O. Vendrell, S.D. Stoychev & L.S. Cederbaum | Generation of highly damaging H2O+ radicals by inner valence shell ionization of water | 2010 | ChemPhysChem 11, 1006 |
|||
| Abstract: {Bye bye friend: Water molecules surround all biological structures. Inner-valence ionization of water, followed by intermolecular Coulombic decay, generates two water radical cations in close proximity. The two fragments strongly repel each other and quickly separate, gaining a large amount of translational and rotational energy} | ||||||
BibTeX:
@article{Vendrell10,
author = {Vendrell, O. and Stoychev, S. D. and Cederbaum, L. S.},
title = {{Generation of highly damaging H2O+ radicals by inner valence shell ionization of water }},
journal = {ChemPhysChem},
publisher = {Wiley-VCH},
year = {2010},
volume = {11},
issue = {5},
pages = {1006},
numpages = {4},
note = {theory},
doi = {https://doi.org/10.1002/cphc.201000034}
}
|
||||||
| S.D. Stoychev, A.I. Kuleff & L.S. Cederbaum | On the intermolecular Coulombic decay of singly and doubly ionized states of water dimer | 2010 | J. Chem. Phys. 133, 154307 |
|||
| Abstract: {A semiquantitative study of the intermolecular Coulombic decay (ICD) of singly and doubly ionized water dimer has been carried out with the help of ab initio computed ionization spectra and potential energy curves (PECs). These PECs are particular cuts through the (H2O)2, (H2O)2+, and (H2O)2++ hypersurfaces along the distance between the two oxygen atoms. A comparison with the recently published experimental data for the ICD in singly ionized water dimers [ T. Jahnke, H. Sann, T. Havermeier et al., Nat. Phys. 6, 139 (2010) ] and in large water clusters [ M. Mucke, M. Braune, S. Barth et al., Nat. Phys. 6, 143 (2010) ] shows that such a simplified description in which the internal degrees of freedom of the water molecules are frozen gives surprisingly useful results. Other possible decay channels of the singly ionized water dimer are also investigated and the influence of the H-atom participating in the hydrogen bond on the spectra of the proton-donor and proton-acceptor molecules in the dimer is discussed. Importantly, the decay processes of one-site dicationic states of water dimer are discussed and an estimate of the ICD-electron spectra is made. More than 33% of the dications produced by Auger decay are found to undergo ICD. The qualitative results show that the ICD following Auger decay in water is also expected to be an additional source of low-energy electrons proven to be extremely important for causing damages to living tissues.} | ||||||
BibTeX:
@article{Stoychev10,
author = {Stoychev, S. D. and Kuleff, A. I. and Cederbaum, L. S.},
title = {{On the intermolecular Coulombic decay of singly and doubly ionized states of water dimer}},
journal = {J. Chem. Phys.},
publisher = {AIP},
year = {2010},
volume = {133},
issue = {15},
pages = {154307},
numpages = {15},
note = {theory},
doi = {https://doi.org/10.1063/1.3499317}
}
|
||||||
| N. Sisourat, N.V. Kryzhevoi, P. Kolorenč, S. Scheit & L.S. Cederbaum | Impact of nuclear dynamics on interatomic Coulombic decay in a He dimer | 2010 | Phys. Rev. A 82, 053401 |
|||
| Abstract: {After simultaneous ionization and excitation of one helium atom within the giant weakly bound helium dimer, the excited ion can relax via interatomic Coulombic decay (ICD) and the excess energy is transferred to ionize the neighboring helium atom. We showed [Sisourat et al. Nature Phys. 6, 508 (2010)] that the distributions of the kinetic energy released by the two ions reflect the nodal structures of the ICD-involved vibrational wave functions. We also demonstrated that energy transfer via ICD between the two helium atoms can take place over more than 14 Å. We report here a more detailed analysis of the ICD process and of the impact of the nuclear dynamics on the electronic decay. Nonadiabatic effects during the ICD process and the accuracy of the potential energy curve of helium dimer and of the computed decay rates are also investigated.} | ||||||
BibTeX:
@article{Sisourat10_2,
author = {Sisourat, N. and Kryzhevoi, N. V. and Kolorenč, P. and Scheit, S. and Cederbaum, L. S.},
title = {{Impact of nuclear dynamics on interatomic Coulombic decay in a He dimer }},
journal = {Phys. Rev. A},
publisher = {American Physical Society},
year = {2010},
volume = {82},
issue = {5},
pages = {053401},
numpages = {8},
note = {theory},
doi = {https://doi.org/10.1103/PhysRevA.82.053401}
}
|
||||||
| C.P. Schwartz, S. Fatehi, R.J. Saykally & D. Prendergast | Importance of Electronic Relaxation for Inter-Coulombic Decay in Aqueous Systems | 2010 | Phys. Rev. Lett. 105, 198102 |
|||
| Abstract: {Inspired by recent photoelectron spectroscopy experiments on hydroxide solutions, we have examined the conditions necessary for enhanced (and, in the case of solutions, detectable) inter-Coulombic decay (ICD)-Auger emission from an atomic site other than that originally excited. We present general guidelines, based on energetic and spatial overlap of molecular orbitals, for this enhancement of inter-Coulombic decay-based energy transfer in solutions. These guidelines indicate that this decay process should be exhibited by broad classes of biomolecules and suggest a design criterion for targeted radiooncology protocols. Our findings show that photoelectron spectroscopy cannot resolve the current hydroxide coordination controversy.} | ||||||
BibTeX:
@article{Schwartz10,
author = {Schwartz, C. P. and Fatehi, S. and Saykally, R. J. and Prendergast, D.},
title = {{Importance of Electronic Relaxation for Inter-Coulombic Decay in Aqueous Systems}},
journal = {Phys. Rev. Lett.},
publisher = {American Physical Society},
year = {2010},
volume = {105},
issue = {19},
pages = {198102},
numpages = {4},
note = {theory},
doi = {https://doi.org/10.1103/PhysRevLett.105.198102}
}
|
||||||
| B. Najjari, A.B. Voitkiv & C. Müller | Two-Center Resonant Photoionization | 2010 | Phys. Rev. Lett. 105, 153002 |
|||
| Abstract: {Photoionization of an atom A, in the presence of a neighboring atom B, can proceed both directly and via resonant excitation of B with subsequent energy transfer to A through two-center electron-electron correlation. We show that in such a case the photoionization process can be very strongly enhanced and acquire interesting characteristic features, both in its time development and the electron spectrum.} | ||||||
BibTeX:
@article{Najjari10,
author = {Najjari, B. and Voitkiv, A. B. and Müller, C.},
title = {{Two-Center Resonant Photoionization}},
journal = {Phys. Rev. Lett.},
publisher = {American Physical Society},
year = {2010},
volume = {105},
issue = {15},
pages = {153002},
numpages = {4},
note = {theory},
doi = {https://doi.org/10.1103/PhysRevLett.105.153002}
}
|
||||||
| C. Müller, A.B. Voitkiv, J.R. Crespo López-Urrutia & Z. Harman | Strongly Enhanced Recombination via Two-Center Electronic Correlations | 2010 | Phys. Rev. Lett. 104, 233202 |
|||
| Abstract: {In the presence of a neighboring atom, electron-ion recombination can proceed resonantly via excitation of an electron in the atom, with subsequent relaxation through radiative decay. It is shown that this two-center dielectronic process can largely dominate over single-center radiative recombination at internuclear distances as large as several nanometers. The relevance of the predicted process is demonstrated by using examples of water-dissolved alkali cations and warm dense matter.} | ||||||
BibTeX:
@article{Mueller10,
author = {Müller, C. and Voitkiv, A. B. and Crespo López-Urrutia, J. R. and Harman, Z.},
title = {{Strongly Enhanced Recombination via Two-Center Electronic Correlations}},
journal = {Phys. Rev. Lett.},
publisher = {American Physical Society},
year = {2010},
volume = {104},
issue = {23},
pages = {233202},
numpages = {4},
note = {theory},
doi = {https://doi.org/10.1103/PhysRevLett.104.233202}
}
|
||||||
| A.I. Kuleff, K. Gokhberg, S. Kopelke & L.S. Cederbaum | Ultrafast Interatomic Electronic Decay in Multiply Excited Clusters | 2010 | Phys. Rev. Lett. 105, 043004 |
|||
| Abstract: {An ultrafast mechanism belonging to the family of interatomic Coulombic decay (ICD) phenomena is proposed. When two excited species are present, an ultrafast energy transfer can take place bringing one of them to its ground state and ionizing the other one. It is shown that if large homoatomic clusters are exposed to an ultrashort and intense laser pulse whose photon energy is in resonance with an excitation transition of the cluster constituents, the large majority of ions will be produced by this ICD mechanism rather than by two-photon ionization. A related collective-ICD process that is operative in heteroatomic systems is also discussed.} | ||||||
BibTeX:
@article{Kuleff10,
author = {Kuleff, A. I. and Gokhberg, K. and Kopelke, S. and Cederbaum, L. S.},
title = {{Ultrafast Interatomic Electronic Decay in Multiply Excited Clusters }},
journal = {Phys. Rev. Lett.},
publisher = {American Physical Society},
year = {2010},
volume = {105},
issue = {4},
pages = {043004},
numpages = {4},
note = {theory},
doi = {https://doi.org/10.1103/PhysRevLett.105.043004}
}
|
||||||
| P. Kolorenč, N.V. Kryzhevoi, N. Sisourat & L.S. Cederbaum | Interatomic Coulombic decay in a He dimer: Ab initio potential energy curves and decay widths | 2010 | Phys. Rev. A 82, 013422 |
|||
| Abstract: {The energy gained by either of the two helium atoms in a helium dimer through simultaneous ionization and excitation can be efficiently transferred to the other helium atom, which then ionizes. The respective relaxation process called interatomic Coulombic decay (ICD) is the subject of the present paper. Specifically, we are interested in ICD of the lowest of the ionized excited states, namely, the He+(n=2)He states, for which we calculated the relevant potential-energy curves and the interatomic decay widths. The full-configuration interaction method was used to obtain the potential-energy curves. The decay widths were computed by utilizing the Fano ansatz, Green's-function methods, and the Stieltjes imaging technique. The behavior of the decay widths with the interatomic distance is examined and is elucidated, whereby special emphasis is given to the asymptotically large interatomic separations. Our calculations show that the electronic ICD processes dominate over the radiative decay mechanisms over a wide range of interatomic distances. The ICD in the helium dimer has recently been measured by Havermeier et al. [Phys. Rev. Lett. 104, 133401 (2010)]. The impact of nuclear dynamics on the ICD process is extremely important and is discussed by Sisourat et al. [Nat. Phys. 6, 508 (2010)] based on the ab initio data computed in the present paper.} | ||||||
BibTeX:
@article{Kolorenc10,
author = {Kolorenč, P. and Kryzhevoi, N. V. and Sisourat, N. and Cederbaum, L. S.},
title = {{Interatomic Coulombic decay in a He dimer: Ab initio potential energy curves and decay widths }},
journal = {Phys. Rev. A},
publisher = {American Physical Society},
year = {2010},
volume = {82},
issue = {1},
pages = {013422},
numpages = {6},
note = {theory},
doi = {https://doi.org/10.1103/PhysRevA.82.013422}
}
|
||||||
| K. Gokhberg, S. Kopelke, N.V. Kryzhevoi, P. Kolorenč & L.S. Cederbaum | Dependence of interatomic decay widths on the symmetry of the decaying state: Analytical expressions and ab initio results | 2010 | Phys. Rev. A 81, 013417 |
|||
| Abstract: {In this article, we investigate the dependence of interatomic Coulombic decay widths on the symmetry of the decaying state. In this type of decay, excited, ionized, and doubly ionized states of an atom or molecule can efficiently relax by ionizing their environment. We concentrate on an atom A and a neighboring atom B and consider such excited, ionized, or doubly ionized states of A that decay by emitting a single photon if A were an isolated atom. Analytical expressions for the various widths are derived for large interatomic distances R. A pronounced dependence of the widths on the symmetry properties of the decaying state is found. This dependence at large R is related to the dependence of the interaction energy of two classical dipoles on their mutual orientation. Comparison with precise ab initio calculations shows that the analytical results hold well at large R, while they deviate from the ab initio values at smaller R due to the effect of orbital overlap.} | ||||||
BibTeX:
@article{Gokhberg10_1,
author = {Gokhberg, K. and Kopelke, S. and Kryzhevoi, N. V. and Kolorenč, P. and Cederbaum, L. S.},
title = {{Dependence of interatomic decay widths on the symmetry of the decaying state: Analytical expressions and ab initio results }},
journal = {Phys. Rev. A},
publisher = {AIP},
year = {2010},
volume = {81},
issue = {1},
pages = {013417},
numpages = {12},
note = {theory},
doi = {https://doi.org/10.1103/PhysRevA.81.013417}
}
|
||||||
| K. Gokhberg & L.S. Cederbaum | Interatomic Coloumbic electron capture | 2010 | Phys. Rev. A 82, 052707 |
|||
| Abstract: {In a previous publication [K. Gokhberg and L. S. Cederbaum, J. Phys. B 42, 231001 (2009)] we presented the interatomic Coulombic electron capture process -- an efficient electron capture mechanism by atoms and ions in the presence of an environment. In the present work we derive and discuss the mechanism in detail. We demonstrate thereby that this mechanism belongs to a family of interatomic electron capture processes driven by electron correlation. In these processes the excess energy released in the capture event is transferred to the environment and used to ionize (or to excite) it. This family includes the processes where the capture is into the lowest or into an excited unoccupied orbital of an atom or ion and proceeds in step with the ionization (or excitation) of the environment, as well as the process where an intermediate autoionizing excited resonance state is formed in the capturing center which subsequently deexcites to a stable state transferring its excess energy to the environment. Detailed derivation of the asymptotic cross sections of these processes is presented. The derived expressions make clear that the environment assisted capture processes can be important for many systems. Illustrative examples are presented for a number of model systems for which the data needed to construct the various capture cross sections are available in the literature.} | ||||||
BibTeX:
@article{Gokhberg10_2,
author = {Gokhberg, K. and Cederbaum, L. S.},
title = {{Interatomic Coloumbic electron capture}},
journal = {Phys. Rev. A},
publisher = {American Physical Society},
year = {2010},
volume = {82},
issue = {5},
pages = {052707},
numpages = {14},
note = {theory},
doi = {https://doi.org/10.1103/PhysRevA.82.052707}
}
|
||||||
| E. Faßhauer, N.V. Kryzhevoi & M. Pernpointner | Possible electronic decay channels in the ionization spectra of small clusters composed of Ar and Xe: A four-component relativistic treatment | 2010 | J. Chem. Phys. 133, 014303 |
|||
| Abstract: {Electronic decay of the inner-valence Ar 3s-1 vacancy is energetically forbidden in an isolated argon atom and in all rare gas dimers where argon is present. However, if an argon atom has at least two suitable rare gas atoms in its neighborhood, the Ar 3s-1 vacancy may decay electronically via an electron transfer mediated decay (ETMD) mechanism. An ArXe2 cluster is considered in the present paper as an example of such systems. The single and double ionization spectra of different ArXe2 isomers as well as of homonuclear Ar2 and Xe2 and heteronuclear ArXe clusters have been calculated by means of propagator methods to reveal possible electronic decay channels. A four-component version of the one-particle propagator utilizing the Dirac-Coulomb Hamiltonian was employed to obtain the single ionization potentials of the clusters studied. Hereby electron correlation, scalar relativistic effects, and spin-orbit couplings are described in a consistent manner. A two-particle propagator in its one-component form, in conjunction with effective core potentials to account consistently for correlation and scalar relativistic effects, was used to calculate the double ionization potentials. ETMD is shown to be the only possible electronic decay process of the Ar 3s-1 vacancy in the ArXe2 cluster. In clusters with more Xe atoms, alternative electronic decay mechanisms may appear.} | ||||||
BibTeX:
@article{Fasshauer10,
author = {Faßhauer, E. and Kryzhevoi, N. V. and Pernpointner, M.},
title = {{Possible electronic decay channels in the ionization spectra of small clusters composed of Ar and Xe: A four-component relativistic treatment}},
journal = {J. Chem. Phys.},
publisher = {AIP},
year = {2010},
volume = {133},
issue = {1},
pages = {014303},
numpages = {7},
note = {theory},
doi = {https://doi.org/10.1063/1.3462246}
}
|
||||||
| V. Averbukh, U. Saalmann & J.M. Rost | Suppression of exponential electronic decay in a charged environment | 2010 | Phys. Rev. Lett. 104, 233002 |
|||
| Abstract: {Inner-shell ionization of atoms and molecules leads to the creation of highly excited ionic states that often decay by electron emission. The dynamics of the decay is usually assumed to be exponential and the process is characterized by a decay rate. Here we show that in a multiply ionized cluster created by interaction with a high-intensity free-electron laser (FEL) radiation, trapping of the emitted electron by the neighboring ions changes the character of the decay dynamics qualitatively to the extent that it can become oscillatory instead of exponential. Implications of the predicted effect on Coster-Kronig and interatomic Coulombic decay processes induced by FELs are investigated.} | ||||||
BibTeX:
@article{Averbukh10_1,
author = {Averbukh, V. and Saalmann, U. and Rost, J. M.},
title = {{Suppression of exponential electronic decay in a charged environment}},
journal = {Phys. Rev. Lett.},
publisher = {American Physical Society},
year = {2010},
volume = {104},
issue = {23},
pages = {233002},
numpages = {4},
note = {theory},
doi = {https://doi.org/10.1103/PhysRevLett.104.233002}
}
|
||||||
| A.B. Voitkiv & B. Najjari | Resonant photoionization in a system of two nonidentical atoms | 2011 | Phys. Rev. A 84, 013415 |
|||
| Abstract: {We consider one-photon ionization in a system consisting of two different atoms, A and B, which are well separated in space. In such a case, photoionization of the atom with a lower ionization potential can be very strongly influenced, via two-center electron-electron correlations, by resonant electron dipole transitions induced in the other atom. We present a detailed consideration of this resonant photoionization process and discuss a number of effects that are inherent to it.} | ||||||
BibTeX:
@article{Voitkiv11,
author = {Voitkiv, A. B. and Najjari, B.},
title = {{Resonant photoionization in a system of two nonidentical atoms}},
journal = {Phys. Rev. A},
publisher = {American Physical Society},
year = {2011},
volume = {84},
issue = {1},
pages = {013415},
numpages = {8},
note = {theory},
doi = {https://doi.org/10.1103/PhysRevA.84.013415}
}
|
||||||
| S.D. Stoychev, A.I. Kuleff & L.S. Cederbaum | Intermolecular Coulombic Decay in Small Biochemically Relevant Hydrogen-Bonded Systems | 2011 | J. Am. Chem. Soc. 133, 6817 |
|||
| Abstract: {Intermolecular Coulombic decay (ICD) is a very fast and efficient relaxation pathway of ionized and excited molecules in environment. The ICD and related phenomena initiated by inner-valence ionization are explored for H2O···HCHO, H2O···H2CNH, H2O···NH3, NH3···H2O, H2O···H2S, H2S···H2O, and H2O···H2O (p-donor···p-acceptor). This set of small hydrogen-bonded systems contains seven types of hydrogen bonding, which are typical for biochemistry, and thus its investigation provides insight into the processes that can take place in living tissues. In particular, an estimate of the ICD in biosystems interacting with water (their usual medium) is made. This decay mode is expected to be a source of low-energy electrons proven to be of extreme genotoxic nature. For the purpose of our study, we have used high-precision ab initio methods in optimizing the geometries and computing the single- and double-ionization spectra of formaldehyde−, formaldimine−, ammonia−, hydrogen sulfide−, and water−water complexes. The energy range of the emitted ICD electrons, as well as the kinetic energy of the dissociating ions produced by ICD, is also reported.} | ||||||
BibTeX:
@article{Stoychev11,
author = {Stoychev, S. D. and Kuleff, A. I. and Cederbaum, L. S.},
title = {{Intermolecular Coulombic Decay in Small Biochemically Relevant Hydrogen-Bonded Systems}},
journal = {J. Am. Chem. Soc.},
publisher = {American Chemical Society},
year = {2011},
volume = {133},
issue = {17},
pages = {6817},
numpages = {8},
note = {theory},
doi = {https://doi.org/10.1021/ja200963y}
}
|
||||||
| M. Pernpointner, A.I. Kuleff & L.S. Cederbaum | Tracing Ultrafast Electron Dynamics by Modern Propagator Approaches | 2011 | Modeling of Molecular Properties , 65 |
|||
| Abstract: { } | ||||||
BibTeX:
@inbook{Pernpointner11,
author = {Pernpointner, M. and Kuleff, A. I. and Cederbaum, L. S.},
title = {{Tracing Ultrafast Electron Dynamics by Modern Propagator Approaches}},
journal = {Modeling of Molecular Properties},
publisher = {Wiley-VCH},
year = {2011},
pages = {65},
numpages = {11},
note = {theory},
doi = {https://doi.org/10.1002/9783527636402.ch5}
}
|
||||||
| C. Müller & A.B. Voitkiv | Resonant two-photon single ionization of two atoms | 2011 | Phys. Rev. Lett. 107, 013001 |
|||
| Abstract: {Resonant two-photon single ionization in a system consisting of two spatially well-separated identical atoms is studied. Because of two-center electron-electron correlations, the ionization may also proceed through photoexcitation of both atoms with subsequent interatomic Coulombic decay. We show that this channel may qualitatively change the dependence of the photoionization on the field intensity as well as the spectra of emitted electrons.} | ||||||
BibTeX:
@article{Mueller11_1,
author = {Müller, C. and Voitkiv, A. B.},
title = {{Resonant two-photon single ionization of two atoms}},
journal = {Phys. Rev. Lett.},
publisher = {American Physical Society},
year = {2011},
volume = {107},
issue = {1},
pages = {013001},
numpages = {4},
note = {theory},
doi = {https://doi.org/10.1103/PhysRevLett.107.013001}
}
|
||||||
| C. Müller, M.A. Macovei & A.B. Voitkiv | Collectively enhanced resonant photoionization in a multiatom ensemble | 2011 | Phys. Rev. A 84, 055401 |
|||
| Abstract: {Photoionization of an atom via interatomic correlations to N neighboring atoms may be strongly enhanced due to constructive interference of quantum pathways. The ionization proceeds via resonant photoexcitation of a neighbor atom and subsequent interatomic Coulombic decay. The enhancement can scale with N2, leading to “superenhanced photoionization”.} | ||||||
BibTeX:
@article{Mueller11_2,
author = {Müller, C. and Macovei, M. A. and Voitkiv, A. B.},
title = {{Collectively enhanced resonant photoionization in a multiatom ensemble}},
journal = {Phys. Rev. A},
publisher = {American Physical Society},
year = {2011},
volume = {84},
issue = {5},
pages = {055401},
numpages = {4},
note = {theory},
doi = {https://doi.org/10.1103/PhysRevA.84.055401}
}
|
||||||
| N.V. Kryzhevoi & L.S. Cederbaum | Using pH Value To Control Intermolecular Electronic Decay | 2011 | Angew. Chem. Int. Ed. 50, 1306 |
|||
| Abstract: {pH deed: Intermolecular Coulombic decay (ICD) is an ultrafast relaxation pathway of a highly excited system. A theoretical investigation of ammonia dimers and trimers shows that the ICD efficiency is regulated by protonation or deprotonation. Varying the ICD rate by changing the environmental pH value provides a control over the relaxation dynamics.} | ||||||
BibTeX:
@article{Kryzhevoi11_1,
author = {Kryzhevoi, N. V. and Cederbaum, L. S.},
title = {{Using pH Value To Control Intermolecular Electronic Decay}},
journal = {Angew. Chem. Int. Ed.},
publisher = {Wiley-VCH},
year = {2011},
volume = {50},
issue = {6},
pages = {1306},
numpages = {4},
note = {theory},
doi = {https://doi.org/10.1002/anie.201004446}
}
|
||||||
| N.V. Kryzhevoi & L.S. Cederbaum | Nonlocal Effects in the Core Ionization and Auger Spectra of Small Ammonia Clusters | 2011 | J. Phys. Chem. B 115, 5441 |
|||
| Abstract: {X-ray photoelectron and Auger spectroscopies are well-suited for exploring the chemical state of a selected system. Chemical shifts of electronic transitions and line broadening in the respective spectra contain a wealth of information on the interaction of the core ionized system with its local environment. The presence of neighbors in the vicinity of the core ionized system is responsible for a number of other remarkable effects such as charge-transfer satellites in core ionization spectra and intermolecular electronic transitions in Auger spectra. In addition, due to the environment, some electronic states resulting from Auger decay may further decay electronically via the intermolecular Coulombic decay mechanism. This decay by emission of an electron would be impossible if the core ionized system were isolated. All of the above phenomena happen in the small ammonia clusters whose core ionization and Auger spectra were computed from first principles and are discussed in the present paper.} | ||||||
BibTeX:
@article{Kryzhevoi11_2,
author = {Kryzhevoi, N. V. and Cederbaum, L. S.},
title = {{Nonlocal Effects in the Core Ionization and Auger Spectra of Small Ammonia Clusters}},
journal = {J. Phys. Chem. B},
publisher = {American Chemical Society},
year = {2011},
volume = {115},
issue = {18},
pages = {5441},
numpages = {7},
note = {theory},
doi = {https://doi.org/10.1021/jp109920p}
}
|
||||||
| A.V. Korol & A.V. Solov'yov | Vacancy decay in endohedral atoms: the role of an atom's non-central position | 2011 | J. Phys. B: At. Mol. Opt. Phys. 44, 085001 |
|||
| Abstract: {We demonstrate that the Auger decay rate in an endohedral atom is very sensitive to the atom's location in the fullerene cage. Two additional decay channels appear in an endohedral system: (a) the channel due to the change in the electric field at the atom caused by the dynamic polarization of the fullerene electron shell by the Coulomb field of the vacancy and (b) the channel within which the released energy is transferred to the fullerene electron via the Coulomb interaction. The relative magnitude of the correction terms is dependent not only on the position of the doped atom but also on the transition energy ω Additional enhancement of the decay rate appears for transitions whose energies are in the vicinity of the fullerene surface plasmons energies of high multipolarity. It is demonstrated that in many cases the additional channels can dominate the direct Auger decay resulting in pronounced broadening of the atomic emission lines. The case study, carried out for Sc2+@C806-, shows that narrow autoionizing resonances in an isolated Sc2+ within the range ω = 30-45 eV are dramatically broadened if the ion is located strongly off the centre. Using the developed model, we carry out the quantitative analysis of the photoionization spectrum for the endohedral complex Sc3N@C80 and demonstrate that the additional channels are partly responsible for the strong modification of the photoionization spectrum profile detected experimentally by Müller et al (2007 J. Phys.: Conf. Ser. 88 012038).} | ||||||
BibTeX:
@article{Korol11,
author = {Korol, A. V. and Solov'yov, A. V.},
title = {{Vacancy decay in endohedral atoms: the role of an atom's non-central position}},
journal = {J. Phys. B: At. Mol. Opt. Phys.},
publisher = {IOP},
year = {2011},
volume = {44},
issue = {8},
pages = {085001},
numpages = {17},
note = {theory},
doi = {https://doi.org/10.1088/0953-4075/44/8/085001}
}
|
||||||
| S. Kopelke, K. Gokhberg, V. Averbukh, F. Tarantelli & L.S. Cederbaum | Ab initio interatomic decay widths of excited states by applying Stieltjes imaging to Lanczos pseudospectra | 2011 | J. Chem. Phys. 134, 094107 |
|||
| Abstract: {Electronically excited states of atoms and molecules in an environment may decay in interatomic processes by transferring excess energy to neighboring species and ionizing them. The corresponding interatomic decay width is the most important characteristic of the decay allowing to calculate its efficiency and the final states' distribution. In this paper we present calculations of interatomic widths by the Fano-Stieltjes method applied to Lanczos pseudospectra, which has been previously shown to provide accurate autoionization widths in atoms and molecules. The use of Lanczos pseudospectra allows one to avoid the full diagonalization bottleneck and makes the method applicable to larger systems. We apply the present method to the calculation of interatomic decay widths in NeMg, NeAr and HCN·Mgn, n = 1, 2 clusters. The results are compared with widths obtained analytically and by other ab initio methods where available.} | ||||||
BibTeX:
@article{Kopelke11,
author = {Kopelke, S. and Gokhberg, K. and Averbukh, V. and Tarantelli, F. and Cederbaum, L. S.},
title = {{Ab initio interatomic decay widths of excited states by applying Stieltjes imaging to Lanczos pseudospectra}},
journal = {J. Chem. Phys.},
publisher = {AIP},
year = {2011},
volume = {134},
issue = {9},
pages = {094107},
numpages = {11},
note = {theory},
doi = {https://doi.org/10.1063/1.3558739}
}
|
||||||
| Ph.V. Demekhin, S.D. Stoychev, A.I. Kuleff & L.S. Cederbaum | Exploring interatomic coulombic decay by free electron lasers | 2011 | Phys. Rev. Lett. 107, 273002 |
|||
| Abstract: {To exploit the high intensity of laser radiation, we propose to select frequencies at which single-photon absorption is of too low energy and two or more photons are needed to produce states of an atom that can undergo interatomic Coulombic decay (ICD) with its neighbors. For Ne2 it is explicitly demonstrated that the proposed multiphoton absorption scheme is much more efficient than schemes used until now, which rely on single-photon absorption. Extensive calculations on Ne2 show how the low-energy ICD electrons and Ne+ pairs are produced for different laser intensities and pulse durations. At higher intensities the production of Ne+ pairs by successive ionization of the two atoms becomes competitive and the respective emitted electrons interfere with the ICD electrons. It is also shown that a measurement after a time delay can be used to determine the contribution of ICD even at high laser intensity.} | ||||||
BibTeX:
@article{Demekhin11,
author = {Demekhin, Ph. V. and Stoychev, S. D. and Kuleff, A. I. and Cederbaum, L. S.},
title = {{Exploring interatomic coulombic decay by free electron lasers}},
journal = {Phys. Rev. Lett.},
publisher = {American Physical Society},
year = {2011},
volume = {107},
issue = {27},
pages = {273002},
numpages = {5},
note = {theory},
doi = {https://doi.org/10.1103/PhysRevLett.107.273002}
}
|
||||||
| Y.-C. Chiang, F. Otto, H.-D. Meyer & L.S. Cederbaum | Interrelation between the distributions of kinetic energy release and emitted electron energy following the decay of electronic states | 2011 | Phys. Rev. Lett. 107, 173001 |
|||
| Abstract: {In an electronic decay process followed by fragmentation the kinetic energy release and electron spectra can be measured. Classically they are the mirror image of each other, a fact which is often used in practice. Quantum expressions are derived for both spectra and analyzed. It is demonstrated that these spectra carry complementary quantum information and are related to the nuclear dynamics in different participating electronic states. Illustrative examples show that the classical picture of a mirror image can break down and shed light on the underlying physics.} | ||||||
BibTeX:
@article{Chiang11,
author = {Chiang, Y.-C. and Otto, F. and Meyer, H.-D. and Cederbaum, L. S.},
title = {{Interrelation between the distributions of kinetic energy release and emitted electron energy following the decay of electronic states}},
journal = {Phys. Rev. Lett.},
publisher = {American Physical Society},
year = {2011},
volume = {107},
issue = {17},
pages = {173001},
numpages = {5},
note = {theory},
doi = {https://doi.org/10.1103/PhysRevLett.107.173001}
}
|
||||||
| I. Cherkes & N. Moiseyev | Electron relaxation in quantum dots by the interatomic Coulombic decay mechanism | 2011 | Phys. Rev. B 83, 113303 |
|||
| Abstract: {Electron relaxation in quantum dot (QD) systems a has significant impact on QD optoelectronic devices such as lasers, photodetectors and solar cells. Several different fundamental mechanisms are known. In this Brief Report we propose another possible relaxation mechanism which is based on the interatomic Coulombic decay (ICD) mechanism first predicted by Cederbaum and his coworkers in 1997 and has been recently observed in atomic van der Waals and in hydrogen-bonded molecular clusters. We show that the electron relaxation in a quantum dot dimer due to the ICD mechanism is on a picoseconds timescale. This mechanism enables us to design IR photodetectors which are extremely efficient for ultraweak radiation with a specific wavelength.} | ||||||
BibTeX:
@article{Cherkes11,
author = {Cherkes, I. and Moiseyev, N.},
title = {{Electron relaxation in quantum dots by the interatomic Coulombic decay mechanism}},
journal = {Phys. Rev. B},
publisher = {American Physical Society},
year = {2011},
volume = {83},
issue = {11},
pages = {113303},
numpages = {4},
note = {theory},
doi = {https://doi.org/10.1103/PhysRevB.83.113303}
}
|
||||||
| A. Bande, K. Gokhberg & L.S. Cederbaum | Dynamics of interatomic Coulombic decay in quantum dots | 2011 | J. Chem. Phys. 135, 144112 |
|||
| Abstract: {In this work we demonstrate that the interatomic Coulombic decay (ICD), an ultrafast electron relaxation process known for atoms and molecules, is possible in general binding potentials. We used the multiconfiguration time-dependent Hartree method for fermions to study ICD in real time in a two-electron model system of two potential wells. Two decay channels were identified and analyzed by using the box stabilization analysis as well as by evaluating the autocorrelation function and measuring the outgoing electron flux during time-propagations. The total and partial ICD widths of an excited state localized in one potential well as a function of the distance between the two potentials was obtained. Finally, we discuss the results with a view to a possible application of ICD in quantum dot technology.} | ||||||
BibTeX:
@article{Bande11,
author = {Bande, A. and Gokhberg, K. and Cederbaum, L. S.},
title = {{Dynamics of interatomic Coulombic decay in quantum dots}},
journal = {J. Chem. Phys.},
publisher = {AIP},
year = {2011},
volume = {135},
issue = {14},
pages = {144112},
numpages = {13},
note = {theory},
doi = {https://doi.org/10.1063/1.3646205}
}
|
||||||
| V. Averbukh, Ph.V. Demekhin, P. Kolorenč, S. Scheit, S.D. Stoychev, A.I. Kuleff, Y.-C. Chiang, K. Gokhberg, S. Kopelke, N. Sisourat & L.S. Cederbaum | Interatomic electronic decay processes in singly and multiply ionized clusters | 2011 | J. Electron Spectrosc. Relat. Phenom. 183, 36 |
|||
| Abstract: {Since their theoretical prediction in 1997, interatomic (intermolecular) Coulombic decay (ICD) and related processes have been in the focus of intensive theoretical and experimental research. The spectacular progress in this direction has been stimulated both by the fundamental importance of the discovered electronic decay phenomena and by the exciting possibility of their practical application, for example in spectroscopy of interfaces. Interatomic decay phenomena take place in inner-shell-ionized clusters due to electronic correlation between two or more cluster constituents. These processes lead to the decay of inner-shell vacancies by electron emission and often also to disintegration of the resulting multiply ionized cluster. Here we review the recent progress in the study of interatomic decay phenomena in singly and multiply ionized clusters.} | ||||||
BibTeX:
@article{Averbukh11,
author = {Averbukh, V. and Demekhin, Ph. V. and Kolorenč, P. and Scheit, S. and Stoychev, S. D. and Kuleff, A. I. and Chiang, Y.-C. and Gokhberg, K. and Kopelke, S. and Sisourat, N. and Cederbaum, L. S.},
title = {{Interatomic electronic decay processes in singly and multiply ionized clusters}},
journal = {J. Electron Spectrosc. Relat. Phenom.},
publisher = {Elsevier},
year = {2011},
volume = {183},
issue = {1-3},
pages = {36},
numpages = {12},
note = {theory},
doi = {https://doi.org/10.1016/j.elspec.2010.03.003}
}
|
||||||
| E. Surdutovich & A.V. Solov'yov | Double strand breaks in DNA resulting from double ionization events | 2012 | Eur. Phys. J. D 66, 206 |
|||
| Abstract: {A mechanism of double strand breaking in DNA due to the action of two electrons is considered. These are the electrons produced in the vicinity of DNA molecules due to ionization of water molecules with a consecutive emission of two electrons, making such a mechanism possible. The transport of secondary electrons, including the additional electrons, is studied in relation to the assessment of radiation damage due to incident ions. This work is a stage in the inclusion of double ionization events into the multiscale approach to ion-beam cancer therapy.} | ||||||
BibTeX:
@article{Surdutovich12,
author = {Surdutovich, E. and Solov'yov, A. V.},
title = {{Double strand breaks in DNA resulting from double ionization events}},
journal = {Eur. Phys. J. D},
publisher = {Springer},
year = {2012},
volume = {66},
issue = {8},
pages = {206},
numpages = {5},
note = {theory},
doi = {https://doi.org/10.1140/epjd/e2012-30180-7}
}
|
||||||
| E. Surdutovich & A.V. Solov'yov | Multiscale physics of ion-beam cancer therapy | 2012 | J. Phys.: Conf. Ser. 373, 012001 |
|||
| Abstract: {We review a multiscale approach to the physics of ion-beam cancer therapy, an approach suggested in order to understand the interplay of a large number of phenomena involved in radiation damage scenario occurring on a range of temporal, spatial, and energy scales. We briefly overview its history and present the current stage of its development. The differences of the multiscale approach from other methods of understanding and assessment of radiation damage are discussed as well as its relationship to other branches of physics, chemistry and biology.} | ||||||
BibTeX:
@proceedings{Surdutovich12_2,
author = {Surdutovich, E. and Solov'yov, A. V.},
title = {{Multiscale physics of ion-beam cancer therapy}},
journal = {J. Phys.: Conf. Ser.},
series= {1st Nano-IBCT Conference 2011},
publisher = {IOP},
year = {2012},
volume = {373},
issue = {1},
pages = {012001},
numpages = {15},
note = {theory},
doi = {https://doi.org/10.1088/1742-6596/373/1/012001}
}
|
||||||
| N. Sisourat, N.V. Kryzhevoi, P. Kolorenč, S. Scheit & L.S. Cederbaum | Giant Interatomic Coulombic Decay | 2012 | J. Phys.: Conf. Ser. 388, 012043 |
|||
| Abstract: {On the example of the giant helium dimer, we present an efficient electronic decay process for excited atoms or molecules embedded in a chemical environment, called Interatomic (intermolecular) Coulombic decay (ICD). After simultaneous ionization and excitation of a helium atom within a helium dimer, the excited ion relaxes by ICD to He+(1s) and the neighbor neutral helium is ionized to He+(1s) as well and emits a secondary electron. A short review on ab initio methods developed during the last 10 years to accurately describe ICD is reported. Finally, the main striking results on the helium dimer obtained experimentally and theoretically are summarized.} | ||||||
BibTeX:
@proceedings{Sisourat12,
author = {Sisourat, N. and Kryzhevoi, N. V. and Kolorenč, P. and Scheit, S. and Cederbaum, L. S.},
title = {{Giant Interatomic Coulombic Decay}},
journal = {J. Phys.: Conf. Ser.},
series= {XXVII International Conference on Photonic, Electronic and Atomic Collisions (ICPEAC 2011)},
publisher = {IOP},
year = {2012},
volume = {388},
issue = {1},
pages = {012043},
numpages = {8},
note = {theory},
doi = {https://doi.org/10.1088/1742-6596/388/1/012043}
}
|
||||||
| G. Sansone, T. Pfeifer, K. Simeonidis & A.I. Kuleff | Electron Correlation in Real Time | 2012 | ChemPhysChem 13, 661 |
|||
| Abstract: {Electron correlation, caused by the interaction among electrons in a multielectron system, manifests itself in all states of matter. A complete theoretical description of interacting electrons is challenging; different approximations have been developed to describe the fundamental aspects of the correlation that drives the evolution of simple (few-electron systems in atoms/molecules) as well as complex (multielectron wave functions in atoms, molecules, and solids) systems. Electron correlation plays a key role in the relaxation mechanisms that characterize excited states of neutral or ionized atoms and molecules populated by absorption of extreme ultraviolet (XUV) or X-ray radiation. The dynamics of these states can lead to different processes such as Fano resonance and Auger decay in atoms or interatomic Coulombic decay or charge migration in molecules and clusters. Many of these relaxation mechanisms are ubiquitous in nature and characterize the interaction of complex systems, such as biomolecules, adsorbates on surfaces, and hydrogen-bonded clusters, with XUV light. These mechanisms evolve typically on the femtosecond (1 fs=10-15 s) or sub-femtosecond timescale. The experimental availability of few-femtosecond and attosecond (1 as=10-18 s) XUV pulses achieved in the last 10 years offers, for the first time, the opportunity to excite and probe in time these dynamics giving the possibility to trace and control multielectron processes. The generation of ultrashort XUV radiation has triggered the development and application of spectroscopy techniques that can achieve time resolution well into the attosecond domain, thereby offering information on the correlated electronic motion and on the correlation between electron and nuclear motion. A deeper understanding of how electron correlation works could have a large impact in several research fields, such as biochemistry and biology, and trigger important developments in the design and optimization of electronic devices.} | ||||||
BibTeX:
@article{Sansone12,
author = {Sansone, G. and Pfeifer, T. and Simeonidis, K. and Kuleff, A. I. },
title = {{Electron Correlation in Real Time}},
journal = {ChemPhysChem},
publisher = {Wiley-VCH},
year = {2012},
volume = {13},
issue = {3},
pages = {661},
numpages = {20},
note = {theory},
doi = {https://doi.org/10.1002/cphc.201100528}
}
|
||||||
| B. Najjari, C. Müller & A.B. Voitkiv | Resonantly enhanced photoionization in correlated three-atomic systems | 2012 | New J. Phys. 14, 105028 |
|||
| Abstract: {Modifications of photoionization arising from resonant electron-electron correlations between neighbouring atoms in an atomic sample are studied. The sample contains atomic species A and B, with the ionization potential of A being smaller than the energy of a dipole-allowed transition in B. The atoms are subject to an external radiation field which is near resonant with the dipole transition in B. Photoionization of an atom A may thus proceed via a two-step mechanism: photoexcitation in the subsystem of species B, followed by interatomic Coulombic decay. As a basic atomic configuration, we investigate resonant photoionization in a three-atomic system A-B-B consisting of an atom A and two neighbouring atoms B. It is found that, under suitable conditions, the presence of neighbouring atoms can strongly affect the photoionization process, including its total probability, time development and photoelectron spectra. In particular, comparing our results with those for photoionization of an isolated atom A and a two-atomic system A-B, respectively, we reveal the characteristic impact made by the third atom.} | ||||||
BibTeX:
@article{Najjari12,
author = {Najjari, B. and Müller, C. and Voitkiv, A. B.},
title = {{Resonantly enhanced photoionization in correlated three-atomic systems}},
journal = {New J. Phys.},
publisher = {IOP},
year = {2012},
volume = {14},
issue = {10},
pages = {105028},
numpages = {14},
note = {theory},
doi = {https://doi.org/10.1088/1367-2630/14/10/105028}
}
|
||||||
| C. Müller, H. Hu, B. Najjari, J.R. Crespo López-Urrutia, Z. Harman & A.B. Voitkiv | Electron recombination in dense photonic, electronic and atomic environments | 2012 | J. Phys.: Conf. Ser. 388, 012003 |
|||
| Abstract: {Free electrons can recombine with ions by either radiative, dielectronic or three-body recombination. In this contribution we discuss variants of these fundamental processes which can occur in dense photonic, electronic and atomic environments. First, dielectronic recombination is generalized to the case where two atomic centers participate in the process. In this situation, the incident electron is captured at one center with simultaneous excitation of a neighboring ion, atom or molecule which subsequently decays via photo-emission. Modifications of radiative recombination in the presence of a strong laser field are discussed afterward. Various relativistic effects, arising from a high energy of the incoming electron and its strong coupling to the intense laser field, are found to clearly manifest themselves in the photo-emission spectra. Finally, we consider three-body “recombination” (i.e. annihilation) of an electron and a positron in the presence of a spectator electron. The process leads to emission of just a single photon and can compete with the usual annihilation into two photons at very high electron densities.} | ||||||
BibTeX:
@proceedings{Mueller12,
author = {Müller, C. and Hu, H. and Najjari, B. and Crespo López-Urrutia, J. R. and Harman, Z. and Voitkiv, A. B.},
title = {{Electron recombination in dense photonic, electronic and atomic environments}},
journal = {J. Phys.: Conf. Ser.},
series= {XXVII International Conference on Photonic, Electronic and Atomic Collisions (ICPEAC 2011)},
publisher = {IOP},
year = {2012},
volume = {388},
issue = {1},
pages = {012003},
numpages = {8},
note = {theory},
doi = {https://doi.org/10.1088/1742-6596/388/1/012003}
}
|
||||||
| N.V. Kryzhevoi & L.S. Cederbaum | Exploring Protonation and Deprotonation Effects with Auger Electron Spectroscopy | 2012 | J. Phys. Chem. Lett. 3, 2733 |
|||
| Abstract: {Auger electron spectroscopy is demonstrated to be a very efficient tool to probe alterations in local chemical environment due to changes in protonation states. We show that electronic and geometric structure changes induced by protonation or deprotonation are well reflected in Auger spectra through characteristic chemical shifts and spectral shape variations. We also present evidence that Auger spectra are sensitive to relative concentrations of compounds in different protonation states. Special attention is paid to the high kinetic energy spectral regions which exhibit remarkable features resulting from core ICD-like transitions in normal species and Auger transitions in deprotonated fragments. The latter contribution was so far ignored when explaining Auger spectra of species embedded in environment. This contribution should be reconsidered taking into account the recently discovered possibility of ultrafast dissociation of core ionized hydrogen bonded systems in media.} | ||||||
BibTeX:
@article{Kryzhevoi12,
author = {Kryzhevoi, N. V. and Cederbaum, L. S.},
title = {{Exploring Protonation and Deprotonation Effects with Auger Electron Spectroscopy}},
journal = {J. Phys. Chem. Lett.},
publisher = {American Chemical Society},
year = {2012},
volume = {3},
issue = {18},
pages = {2733},
numpages = {5},
note = {theory},
doi = {https://doi.org/10.1021/jz301130t}
}
|
||||||
| S. Kopelke, Y.-C. Chiang, K. Gokhberg & L.S. Cederbaum | Quenching molecular photodissociation by intermolecular Coulombic decay | 2012 | J. Chem. Phys. 137, 034302 |
|||
| Abstract: {In this paper we study the impact of interatomic Coulombic decay (ICD) on molecular photodissociation. The investigation reveals the hitherto unrecognized ability of ICD to quench processes involving nuclear rearrangements. Numerical computations of the nuclear dynamics, initiated by photoexciting the B1Σ+ Rydberg state of CO in CO·Mg complexes, are carried out. The efficiencies of ICD and photoinduced predissociation are compared for the four lowest vibrational levels of the corresponding electronic state. We also show the impact of CO vibrations on the ICD electron spectrum. Finally, we discuss the growing efficiency of ICD to quench the dissociation as the number of neighboring Mg atoms is increased.} | ||||||
BibTeX:
@article{Kopelke12,
author = {Kopelke, S. and Chiang, Y.-C. and Gokhberg, K. and Cederbaum, L. S. },
title = {{Quenching molecular photodissociation by intermolecular Coulombic decay}},
journal = {J. Chem. Phys.},
publisher = {AIP},
year = {2012},
volume = {137},
issue = {3},
pages = {034302},
numpages = {9},
note = {theory},
doi = {https://doi.org/10.1063/1.4731636}
}
|
||||||
| V. Averbukh & P. Kolorenč | Electronic Decay in Multiply Charged Polyatomic Systems | 2012 | Adv. Quantum Chem. 63, 309 |
|||
| Abstract: {Inner-shell ionization of atoms, molecules, and clusters often leads to creation of highly excited ionic states that are embedded into double (or even multiple) ionization continua and decay by electron emission. The most common electronic decay process triggered by core ionization is known as Auger effect. The dynamics of the Auger decay is usually assumed to be exponential, and the process is characterized by a decay rate. The advent of the high-intensity x-ray free-electron lasers and their envisaged applications in molecular imaging have made it necessary to consider Auger-type processes in polyatomic systems under conditions of multiple ionization, both in the core and in the valence shells. Here, we review our recent theoretical work on the theory of electronic decay in multiply charged molecules and clusters. Particular attention is given to the effects of the spectator vacancies on the Auger decay rates, trapping of the Auger electron in a multiply charged system, and collective decay of two vacancies.} | ||||||
BibTeX:
@inbook{Averbukh12_2,
author = {Averbukh, V. and Kolorenč, P.},
title = {{Electronic Decay in Multiply Charged Polyatomic Systems}},
journal = {Adv. Quantum Chem.},
publisher = {Academic Press},
year = {2012},
volume = {63},
pages = {309},
numpages = {34},
note = {theory},
doi = {https://doi.org/10.1016/B978-0-12-397009-1.00006-0}
}
|
||||||
| V. Averbukh, L.S. Cederbaum, Ph.V. Demekhin, S. Scheit, P. Kolorenč, Y.-C. Chiang, K. Gokhberg, S. Kopelke, N.V. Kryzhevoi, A.I. Kuleff, N. Sisourat & S.D. Stoychev | Interatomic Electronic Decay Processes in Clusters | 2012 | Dynamical Processes in Atomic and Molecular Physics , 29 |
|||
| Abstract: {Since their theoretical prediction in 1997, Interatomic (intermolecular) Coulombic Decay (ICD) and related processes have been in the focus of intensive theoretical and experimental research. The spectacular progress in this direction has been stimulated both by the fundamental importance of the discovered electronic decay phenomena and by the exciting possibility of their practical application, for example in spectroscopy of interfaces. Interatomic decay phenomena take place in inner-shellionized and inner-shell-excited clusters due to electronic correlation between two or more cluster constituents. These processes lead to relaxation by electron emission and often also to disintegration of the resulting positively charged cluster. Here we review the recent progress in the study of interatomic decay phenomena in excited, singly and multiply charged clusters.} | ||||||
BibTeX:
@inbook{Averbukh12_1,
author = {Averbukh, V. and Cederbaum, L. S. and Demekhin, Ph. V. and Scheit, S. and Kolorenč, P. and Chiang, Y.-C. and Gokhberg, K. and Kopelke, S. and Kryzhevoi, N. V. and Kuleff, A. I. and Sisourat, N. and Stoychev, S. D.},
title = {{Interatomic Electronic Decay Processes in Clusters}},
journal = {Dynamical Processes in Atomic and Molecular Physics},
publisher = {Bentham Science Publishers},
year = {2012},
pages = {29},
numpages = {28},
note = {theory},
doi = {https://doi.org/10.2174/97816080524551120101}
}
|
||||||
| O. Svoboda, D. Hollas, M. Ončák & P. Slavíček | Reaction Selectivity in Ionized Water Dimer: Nonadiabatic Ab Initio Dynamics Simulations | 2013 | Phys. Chem. Chem. Phys. 15, 11531 |
|||
| Abstract: {We study dynamical processes following water dimer ionization. The nonadiabatic dynamical simulations of the water dimer radical cation are performed using a surface hopping technique and a Complete Active Space – Self Consistent Field (CASSCF) method for the description of electronic structure. The main goal of this study is to find out whether a state-dependent reactivity is observed for the water dimer radical cation. We provide a detailed mapping of the potential energy surfaces (PESs) in the relevant coordinates for different electronic states. Dynamical patterns are discussed on the basis of static PES cuts and available experimental data. As a product of the reaction, we observed either proton transferred structure (H3O+⋅⋅⋅OH•) or various dissociated structures (H3O+ + OH•, H2O•+ + H2O, H• + OH• + H2O•+). The relative yields are controlled by the populated electronic state of the radical cation. The proton transfer upon the HOMO electron ionization is an ultrafast process, taking less than 100 fs, in cases of higher energy ionization the dynamical processes occur on longer timescales (200-300 fs). We also discuss the implications of our simulations for the efficiency of the recently identified intermolecular coulomb decay (ICD) process in the water dimer.} | ||||||
BibTeX:
@article{Svoboda13,
author = {Svoboda, O. and Hollas, D. and Ončák, M. and Slavíček, P.},
title = {{Reaction Selectivity in Ionized Water Dimer: Nonadiabatic Ab Initio Dynamics Simulations}},
journal = {Phys. Chem. Chem. Phys.},
publisher = {RSC},
year = {2013},
volume = {15},
issue = {27},
pages = {11531},
numpages = {12},
note = {theory},
doi = {https://doi.org/10.1039/C3CP51440D}
}
|
||||||
| V. Stumpf, P. Kolorenč, K. Gokhberg & L.S. Cederbaum | Efficient pathway to neutralization of multiply charged ions produced in Auger processes | 2013 | Phys. Rev. Lett. 110, 258302 |
|||
| Abstract: {After core ionization of an atom or molecule by an x-ray photon, multiply charged ions are produced in the Auger decay process. These ions tend to neutralize their charge when embedded in an environment. We demonstrate that, depending on the atom or molecule and its neighbors, electron transfer mediated decay (ETMD) provides a particularly efficient neutralization pathway for the majority of the ions produced by Auger decay. The mechanism is rather general. As a show case example, we conducted an ab initio study of the NeKr2 cluster after core ionization of the Ne atom. This example has been chosen because it is amenable to both ab initio calculations and coincidence experiments. We find that even for frozen nuclei, the neutralization rate can be as fast as 0.130 ps-1. We also show that nuclear dynamics may increase the rate by about an order of magnitude. The generality of the mechanism makes this neutralization pathway important in weakly bonded environments.} | ||||||
BibTeX:
@article{Stumpf13,
author = {Stumpf, V. and Kolorenč, P. and Gokhberg, K. and Cederbaum, L. S.},
title = {{Efficient pathway to neutralization of multiply charged ions produced in Auger processes}},
journal = {Phys. Rev. Lett.},
publisher = {American Physical Society},
year = {2013},
volume = {110},
issue = {25},
pages = {258302},
numpages = {5},
note = {theory},
doi = {https://doi.org/10.1103/PhysRevLett.110.258302}
}
|
||||||
| N. Sisourat | Nuclear dynamics of decaying states: A semiclassical approach | 2013 | J. Chem. Phys. 139, 074111 |
|||
| Abstract: {A semiclassical method is proposed for carrying out molecular fragmentation simulations following electronic decay processes. The nuclear motion is treated classically during and after the electronic decay while a quantum mechanical description is used for the electron dynamics. The method is compared with full quantum results for benchmark examples. Good agreement is achieved. Such a method should be very useful for studying large systems for which a quantum description is not feasible.} | ||||||
BibTeX:
@article{Sisourat13,
author = {Sisourat, N. },
title = {{Nuclear dynamics of decaying states: A semiclassical approach}},
journal = {J. Chem. Phys.},
publisher = {AIP},
year = {2013},
volume = {139},
issue = {7},
pages = {074111},
numpages = {5},
note = {theory},
doi = {https://doi.org/10.1063/1.4818491}
}
|
||||||
| F.M. Pont, A. Bande & L.S. Cederbaum | Controlled energy-selected electron capture and release in double quantum dots | 2013 | Phys. Rev. B 88, 241304 |
|||
| Abstract: {Highly accurate quantum electron dynamics calculations demonstrate that energy can be efficiently transferred between quantum dots. Specifically, in a double quantum dot an incoming electron is captured by one dot and the excess energy is transferred to the neighboring dot and used to remove an electron from this dot. This process is due to long-range electron correlation and shown to be operative at rather large distances between the dots. The efficiency of the process is greatly enhanced by preparing the double quantum dot such that the incoming electron is initially captured by a two-electron resonance state of the system. In contrast to atoms and molecules in nature, double quantum dots can be manipulated to achieve this enhancement. This mechanism leads to a surprisingly narrow distribution of the energy of the electron removed in the process which is explained by resonance theory. We argue that the process could be exploited in practice.} | ||||||
BibTeX:
@article{Pont13,
author = {Pont, F. M. and Bande, A. and Cederbaum, L. S.},
title = {{Controlled energy-selected electron capture and release in double quantum dots}},
journal = {Phys. Rev. B},
publisher = {American Physical Society},
year = {2013},
volume = {88},
issue = {24},
pages = {241304},
numpages = {5},
note = {theory},
doi = {https://doi.org/10.1103/PhysRevB.88.241304}
}
|
||||||
| N.V. Kryzhevoi, D. Mateo, M. Pi, M. Barranco & L.S. Cederbaum | Probing the interface of doped isotopically mixed helium droplets by the directional anisotropy of interatomic Coulombic decay | 2013 | Phys. Chem. Chem. Phys. 15, 18167 |
|||
| Abstract: {Interatomic Coulombic decay (ICD) represents an efficient electronic relaxation mechanism of an ionized or an excited system embedded in an environment. The type of this environment and its size have a great impact on the ICD performance. It is stressed that ICD is sensitive to the arrangement of neighboring atoms when the initially created vacancy has a polarization direction. This is demonstrated in the present paper for the case of a 3p-ionized Ca surrounded by He atoms. Useful explicit expressions are derived for the ICD widths which show that the neighbors located along the polarization direction of the ionized orbital have the largest contribution to the ICD rate. By comparison with ab initio results for small clusters, we also show that in a helium environment, the pairwise approximation represents a reliable approach for computing ICD widths. Using this approximation and the density distribution of the helium atoms obtained within density functional theory, we explore ICD in large isotopically mixed helium droplets doped with Ca. A special emphasis is given to the difference between the ICD widths for the Ca3p orbitals directed perpendicular and parallel to the droplet surface. Depending on the size and isotopic composition of the droplet, Ca resides in the interfacial layer between the 4He core and the 3He outer shell. Hence, ICD studies in these droplets may provide valuable information on the properties of this interface.} | ||||||
BibTeX:
@article{Kryzhevoi13,
author = {Kryzhevoi, N. V. and Mateo, D. and Pi, M. and Barranco, M. and Cederbaum, L. S.},
title = {{Probing the interface of doped isotopically mixed helium droplets by the directional anisotropy of interatomic Coulombic decay}},
journal = {Phys. Chem. Chem. Phys.},
publisher = {RSC},
year = {2013},
volume = {15},
issue = {41},
pages = {18167},
numpages = {7},
note = {theory},
doi = {https://doi.org/10.1039/C3CP52898G}
}
|
||||||
| Ph.H.P. Harbach, M. Schneider, S. Faraji & A. Dreuw | Intermolecular Coulombic Decay in Biology: The Initial Electron Detachment from FADH- in DNA Photolyases | 2013 | J. Phys. Chem. Lett. 4, 943 |
|||
| Abstract: {Intermolecular coulombic decay (ICD) is an efficient mechanism of low-energy electron generation in condensed phases and is discussed as their potential source in living cells, tissues, and materials. The first example of ICD as an operating mechanism in real biological systems, that is, in the DNA repair enzymes photolyases, is presented. Photolyase function involves light-induced electron detachment from a reduced flavin adenine dinucleotide (FADH-), followed by its transfer to the DNA-lesion triggering repair of covalently bound nucleobase dimers. Modern quantum chemical methods are employed to demonstrate that the transferred electron is efficiently generated via a resonant ICD process between the antenna pigment and the FADH- cofactors.} | ||||||
BibTeX:
@article{Harbach13,
author = {Harbach, Ph.H.P. and Schneider, M. and Faraji, S. and Dreuw, A.},
title = {{Intermolecular Coulombic Decay in Biology: The Initial Electron Detachment from FADH- in DNA Photolyases}},
journal = {J. Phys. Chem. Lett.},
publisher = {American Chemical Society},
year = {2013},
volume = {4},
issue = {6},
pages = {943},
numpages = {7},
note = {theory},
doi = {https://doi.org/10.1021/jz400104h}
}
|
||||||
| A. Ghosh, S. Pal & N. Vaval | Study of interatomic Coulombic decay of Ne(H2O)n (n=1,3) clusters using equation-of-motion coupled-cluster method | 2013 | J. Chem. Phys. 139, 064112 |
|||
| Abstract: {Interatomic Coulombic decay (ICD) is an efficient and ultrafast radiationless decay mechanism which can be initiated by removal of an electron from the inner-valence shell of an atom or molecule. Generally, the ICD mechanism is prevailed in weakly bound clusters. A very promising approach, known as CAP/EOM-CC, consists of the combination of complex absorbing potential (CAP) with the equation-of-motion coupled-cluster (EOM-CC) method, is applied for the first time to study the nature of the ICD mechanism. We have applied this technique to determine the lifetime of an autoionized, inner-valence excited state of the NeH2O, Ne(H2O)2, and Ne(H2O)3 systems. The lifetime is found to be very short and decreases significantly with the number of neighboring water molecules.} | ||||||
BibTeX:
@article{Ghosh13a,
author = {Ghosh, A. and Pal, S. and Vaval, N.},
title = {{Study of interatomic Coulombic decay of Ne(H2O)n (n=1,3) clusters using equation-of-motion coupled-cluster method}},
journal = {J. Chem. Phys.},
publisher = {AIP},
year = {2013},
volume = {139},
issue = {6},
pages = {064112},
numpages = {5},
note = {theory},
doi = {https://doi.org/10.1063/1.4817966}
}
|
||||||
| E. Fasshauer, M. Pernpointner & K. Gokhberg | Interatomic decay of inner-valence ionized states in ArXe clusters: Relativistic approach | 2013 | J. Chem. Phys. 138, 014305 |
|||
| Abstract: {In this work we investigate interatomic electronic decay processes taking place in mixed argon-xenon clusters upon the inner-valence ionization of an argon center. We demonstrate that both interatomic Coulombic decay and electron-transfer mediated decay (ETMD) are important in larger rare gas clusters as opposed to dimers. Calculated secondary electron spectra are shown to depend strongly on the spin-orbit coupling in the final states of the decay as well as the presence of polarizable environment. It follows from our calculations that ETMD is a pure interface process taking place between the argon-xenon layers. The interplay of all these effects is investigated in order to arrive at a suitable physical model for the decay of inner-valence vacancies taking place in mixed ArXe clusters.} | ||||||
BibTeX:
@article{Fasshauer13,
author = {Fasshauer, E. and Pernpointner, M. and Gokhberg, K.},
title = {{Interatomic decay of inner-valence ionized states in ArXe clusters: Relativistic approach}},
journal = {J. Chem. Phys.},
publisher = {AIP},
year = {2013},
volume = {138},
issue = {1},
pages = {014305},
numpages = {10},
note = {theory},
doi = {https://doi.org/10.1063/1.4772654}
}
|
||||||
| A. Dreuw & S. Faraji | A quantum chemical perspective on (6-4) photolesion repair by photolyases | 2013 | Phys. Chem. Chem. Phys. 15, 19957 |
|||
| Abstract: {(6-4)-Photolyases are fascinating enzymes which repair (6-4)-DNA photolesions utilizing light themselves. It is well known that upon initial photo-excitation of an antenna pigment an electron is transferred from an adjacent FADH- cofactor to the photolesion initiating repair, i.e. restoration of the original undamaged DNA bases. Concerning the molecular details of this amazing repair mechanism, the early steps of energy transfer and catalytic electron generation are well understood, the terminal repair mechanism, however, is still a matter of ongoing debate. In this perspective article, recent results of quantum chemical investigations are presented, and their meaning for the repair mechanism under natural conditions is outlined. Consequences of natural light conditions, temperature and thermal equilibration are highlighted when issues like the initial protonation state of the relevant histidines and the lesion, or the direction of electron transfer are discussed.} | ||||||
BibTeX:
@article{Dreuw13,
author = {Dreuw, A. and Faraji, S.},
title = {{A quantum chemical perspective on (6-4) photolesion repair by photolyases}},
journal = {Phys. Chem. Chem. Phys.},
publisher = {RSC},
year = {2013},
volume = {15},
issue = {46},
pages = {19957},
numpages = {13},
note = {theory},
doi = {https://doi.org/10.1039/C3CP53313A}
}
|
||||||
| Ph.V. Demekhin, K. Gokhberg, G. Jabbari, S. Kopelke, A.I. Kuleff & L.S. Cederbaum | Overcoming blockade in producing doubly excited dimers by a single intense pulse and their decay | 2013 | J. Phys. B: At. Mol. Opt. Phys. 46, 021001 |
|||
| Abstract: {Excitation of two identical species in a cluster by the absorption of two photons of the same energy is strongly suppressed since the excitation of one subunit blocks the excitation of the other one due to the binding Coulomb interaction. Here, we propose a very efficient way to overcome this blockade in producing doubly excited homoatomic clusters by a single intense laser pulse. For Ne2 it is explicitly demonstrated that the optimal carrier frequency of the pulse is given by half of the target state's energy, which allows one to doubly excite more than half of the dimers at moderate field intensities. These dimers then undergo ultrafast interatomic decay bringing one Ne to its ground state and ionizing the other one. The reported ab initio electron spectra present reliable predictions for future experiments by strong laser pulses.} | ||||||
BibTeX:
@article{Demekhin13,
author = {Demekhin, Ph. V. and Gokhberg, K. and Jabbari, G. and Kopelke, S. and Kuleff, A. I. and Cederbaum, L. S.},
title = {{Overcoming blockade in producing doubly excited dimers by a single intense pulse and their decay}},
journal = {J. Phys. B: At. Mol. Opt. Phys.},
publisher = {IOP},
year = {2013},
volume = {46},
issue = {2},
pages = {021001},
numpages = {6},
note = {theory},
doi = {https://doi.org/10.1088/0953-4075/46/2/021001}
}
|
||||||
| A. Bande, F.M. Pont, P. Dolbundalchok, K. Gokhberg & L.S. Cederbaum | Electron Dynamics of Interatomic Coulombic Decay in Quantum Dots: Singlet Initial State | 2013 | Eur. Phys. J. Conf. 41, 04031 |
|||
| Abstract: {In this paper we investigated the interatomic Coulombic decay (ICD) of a resonance singlet state in a model potential for two few-electron semiconductor quantum dots (QDs) by means of electron dynamics. We demonstrate that ICD is the major decay process of the resonance for the singlet wave function and compare the total and partial decay widths as a function of the QD separation with that from our previous study on the corresponding triplet states [1].} | ||||||
BibTeX:
@proceedings{Bande13a,
author = {Bande, A. and Pont, F. M. and Dolbundalchok, P. and Gokhberg, K. and Cederbaum, L. S.},
title = {{Electron Dynamics of Interatomic Coulombic Decay in Quantum Dots: Singlet Initial State}},
journal = {Eur. Phys. J. Conf.},
series= {XVIIIth International Conference on Ultrafast Phenomena},
publisher = {EDP Sciences},
year = {2013},
volume = {41},
pages = {04031},
numpages = {3},
note = {theory},
doi = {https://doi.org/10.1051/epjconf/20134104031}
}
|
||||||
| A. Bande | Electron dynamics of interatomic Coulombic decay in quantum dots induced by a laser field | 2013 | J. Chem. Phys. 138, 214104 |
|||
| Abstract: {In this paper we investigated the dynamics of an electron in the presence of a time-dependent laser field in a model potential for a two-level single-electron semiconductor quantum dot (QD) that is capable of undergoing interatomic Coulombic decay (ICD) together with an electron bound to a neighboring QD. We demonstrate that ICD can be initiated by coupling the two-level QD to either a continuous or a pulsed moderate to strong laser and we obtain the total and partial decay widths of the resonance excited state in agreement with that from the solely decay of the resonance [A. Bande, K. Gokhberg, and L. S. Cederbaum, J. Chem. Phys. 135, 144112 (2011)]. A detailed discussion of the effects of direct ionization by the laser in single- or multi-photon process as well as Rabi oscillations is furthermore presented.} | ||||||
BibTeX:
@article{Bande13b,
author = {Bande, A. },
title = {{Electron dynamics of interatomic Coulombic decay in quantum dots induced by a laser field}},
journal = {J. Chem. Phys.},
publisher = {AIP},
year = {2013},
volume = {138},
issue = {14},
pages = {214104},
numpages = {11},
note = {theory},
doi = {https://doi.org/10.1063/1.4807611}
}
|
||||||
| J.P. Zobel, N.V. Kryzhevoi & M. Pernpointner | Communication: Electron transfer mediated decay enabled by spin-orbit interaction in small krypton/xenon clusters | 2014 | J. Chem. Phys. 140, 161103 |
|||
| Abstract: {In this work we study the influence of relativistic effects, in particular spin-orbit coupling, on electronic decay processes in KrXe2 clusters of various geometries. For the first time it is shown that inclusion of spin-orbit coupling has decisive influence on the accessibility of a specific decay pathway in these clusters. The radiationless relaxation process is initiated by a Kr 4s ionization followed by an electron transfer from xenon to krypton and a final second ionization of the system. We demonstrate the existence of competing electronic decay pathways depending in a subtle way on the geometry and level of theory. For our calculations a fully relativistic framework was employed where omission of spin-orbit coupling leads to closing of two decay pathways. These findings stress the relevance of an adequate relativistic description for clusters with heavy elements and their fragmentation dynamics.} | ||||||
BibTeX:
@article{Zobel14,
author = {Zobel, J. P. and Kryzhevoi, N. V. and Pernpointner, M.},
title = {{Communication: Electron transfer mediated decay enabled by spin-orbit interaction in small krypton/xenon clusters}},
journal = {J. Chem. Phys.},
publisher = {AIP},
year = {2014},
volume = {140},
issue = {16},
pages = {161103},
numpages = {4},
note = {theory},
doi = {https://doi.org/10.1063/1.4873134}
}
|
||||||
| V. Stumpf, N.V. Kryzhevoi, K. Gokhberg & L.S. Cederbaum | Enhanced one-photon double ionization of atoms and molecules in an environment of different species | 2014 | Phys. Rev. Lett. 112, 193001 |
|||
| Abstract: {The correlated nature of electronic states in atoms and molecules is manifested in the simultaneous emission of two electrons after absorption of a single photon close to the respective threshold. Numerous observations in atoms and small molecules demonstrate that the double ionization efficiency close to threshold is rather small. In this Letter we show that this efficiency can be dramatically enhanced in the environment. To be specific, we concentrate on the case where the species in question has one or several He atoms as neighbors. The enhancement is achieved by an indirect process, where a He atom of the environment absorbs a photon and the resulting He+ cation is neutralized fast by a process known as electron transfer mediated decay, producing thereby doubly ionized species. The enhancement of the double ionization is demonstrated in detail for the example of the Mg·He cluster. We show that the double ionization cross section of Mg becomes 3 orders of magnitude larger than the respective cross section of the isolated Mg atom. The impact of more neighbors is discussed and the extension to other species and environments is addressed.} | ||||||
BibTeX:
@article{Stumpf14,
author = {Stumpf, V. and Kryzhevoi, N. V. and Gokhberg, K. and Cederbaum, L. S.},
title = {{Enhanced one-photon double ionization of atoms and molecules in an environment of different species}},
journal = {Phys. Rev. Lett.},
publisher = {American Physical Society},
year = {2014},
volume = {112},
issue = {19},
pages = {193001},
numpages = {5},
note = {theory},
doi = {https://doi.org/10.1103/PhysRevLett.112.193001}
}
|
||||||
| Y. Sajeev, A. Ghosh, N. Vaval & S. Pal | Coupled cluster methods for autoionisation resonances | 2014 | Int. Rev. Phys. Chem. 33, 397 |
|||
| Abstract: {The quantum chemical calculation of autoionisation resonances in many-electron systems is a highly challenging task due to the ionisation continuum involved. Recently, advances were reported where conventionally used ab initio codes can be employed to compute autoionisation resonances. This is made possible by the use of analytical continuation tools such as complex scaling and complex absorbing potential (CAP) in the electronic structure codes. We review the formulation and the use of complex scaling and CAP in coupled cluster methods for the electron correlated calculation of energy position and autoionisation decay rate of resonance states. The application of analytically continued coupled cluster method for the correlated calculation of interatomic or intermolecular Coulombic decay process is also discussed.} | ||||||
BibTeX:
@article{Sajeev14,
author = {Sajeev, Y. and Ghosh, A. and Vaval, N. and Pal, S.},
title = {{Coupled cluster methods for autoionisation resonances}},
journal = {Int. Rev. Phys. Chem.},
publisher = {Taylor & Francis},
year = {2014},
volume = {33},
issue = {3},
pages = {397},
numpages = {29},
note = {theory},
doi = {https://doi.org/10.1080/0144235X.2014.935585}
}
|
||||||
| T. Miteva, Y.-C. Chiang, P. Kolorenč, A.I. Kuleff, K. Gokhberg & L.S. Cederbaum | Interatomic Coulombic decay following resonant core excitation of Ar in argon dimer | 2014 | J. Chem. Phys. 141, 064307 |
|||
| Abstract: {A scheme utilizing excitation of core electrons followed by the resonant-Auger — interatomic Coulombic decay (RA-ICD) cascade was recently proposed as a means of controlling the generation site and energies of slow ICD electrons. This control mechanism was verified in a series of experiments in rare gas dimers. In this article, we present fully ab initio computed ICD electron and kinetic energy release spectra produced following 2p3/2→4s, 2p½→4s, and 2p3/2→3d core excitations of Ar in Ar2. We demonstrate that the manifold of ICD states populated in the resonant Auger process comprises two groups. One consists of lower energy ionization satellites characterized by fast interatomic decay, while the other consists of slow decaying higher energy ionization satellites. We show that accurate description of nuclear dynamics in the latter ICD states is crucial for obtaining theoretical electron and kinetic energy release spectra in good agreement with the experiment.} | ||||||
BibTeX:
@article{Miteva14_1,
author = {Miteva, T. and Chiang, Y.-C. and Kolorenč, P. and Kuleff, A. I. and Gokhberg, K. and Cederbaum, L. S.},
title = {{Interatomic Coulombic decay following resonant core excitation of Ar in argon dimer}},
journal = {J. Chem. Phys.},
publisher = {AIP},
year = {2014},
volume = {141},
issue = {6},
pages = {064307},
numpages = {10},
note = {theory},
doi = {https://doi.org/10.1063/1.4891986}
}
|
||||||
| T. Miteva, Y.-C. Chiang, P. Kolorenč, A.I. Kuleff, L.S. Cederbaum & K. Gokhberg | The effect of the partner atom on the spectra of interatomic Coulombic decay triggered by resonant Auger processes | 2014 | J. Chem. Phys. 141, 164303 |
|||
| Abstract: {The resonant-Auger — interatomic Coulombic decay (ICD) cascade was recently suggested as an efficient means of controlling the course of the ICD process. Recent theoretical and experimental works show that control over the energies of the emitted ICD electrons can be achieved either by varying the photon energy to produce different initial core excitations or by changing the neighboring species. This work presents a theoretical investigation on the role of the rare-gas neighbor and clarifies how the latter influences the ICD process. For this purpose, we compare fully ab initio computed ICD-electron and kinetic energy release spectra following the 2p3/2→4s, 2p½→4s and 2p3/2→3d of Ar in ArKr and Ar2. We demonstrate that the presence of the chemically “softer” partner atom results in an increase in the energies of the emitted ICD electrons, and also in the appearance of additional ICD-active states. The latter leads to a threefold increase in the ICD yield for the case of the 2p3/2,1/2→4s parent core excitations.} | ||||||
BibTeX:
@article{Miteva14_2,
author = {Miteva, T. and Chiang, Y.-C. and Kolorenč, P. and Kuleff, A. I. and Cederbaum, L. S. and Gokhberg, K.},
title = {{The effect of the partner atom on the spectra of interatomic Coulombic decay triggered by resonant Auger processes}},
journal = {J. Chem. Phys.},
publisher = {AIP},
year = {2014},
volume = {141},
issue = {16},
pages = {164303},
numpages = {8},
note = {theory},
doi = {https://doi.org/10.1063/1.4898154}
}
|
||||||
| M.H. Javani, J.B. Wise, R. De, M.E. Madjet, S.T. Manson & H.S. Chakraborty | Resonant Auger-intersite-Coulombic hybridized decay in the photoionization of endohedral fullerenes | 2014 | Phys. Rev. A 89, 063420 |
|||
| Abstract: {Considering the photoionization of Ar@C60, we predict resonant femtosecond decays of both Ar and C60 vacancies through the continua of atom-fullerene hybrid final states. For Ar 3s→np excitations, these resonances are far stronger than the Ar-to-C60 resonant intersite-Coulombic decays (ICD), while for C60 excitations they are strikingly larger than the corresponding Auger features. The results indicate the power of hybridization to enhance decay rates and modify lifetimes and line profiles, offering a unique probe, more powerful than regular ICDs, for multicenter decay processes.} | ||||||
BibTeX:
@article{Javani14,
author = {Javani, M. H. and Wise, J. B. and De, R. and Madjet, M. E. and Manson, S. T. and Chakraborty, H. S.},
title = {{Resonant Auger-intersite-Coulombic hybridized decay in the photoionization of endohedral fullerenes}},
journal = {Phys. Rev. A},
publisher = {American Physical Society},
year = {2014},
volume = {89},
issue = {6},
pages = {063420},
numpages = {4},
note = {theory},
doi = {https://doi.org/10.1103/PhysRevA.89.063420}
}
|
||||||
| G. Jabbari, S. Klaiman, Y.-C. Chiang, F. Trinter, T. Jahnke & K. Gokhberg | Ab initio calculation of ICD widths in photoexcited HeNe | 2014 | J. Chem. Phys. 140, 224305 |
|||
| Abstract: {Excitation of HeNe by synchrotron light just below the frequency of the 1s→3p transition of isolated He has been recently shown to be followed by resonant interatomic Coulombic decay (ICD). The vibrationally resolved widths of the ICD states were extracted with high precision from the photoion spectra. In this paper, we report the results of ab initio calculations of these widths. We show that interaction between electronic states at about the equilibrium distance of HeNe makes dark states of He accessible for the photoexcitation and subsequent electronic decay. Moreover, the values of the calculated widths are shown to be strongly sensitive to the presence of the non-adiabatic coupling between the electronic states participating in the decay. Therefore, only by considering the complete manifold of interacting decaying electronic states a good agreement between the measured and computed ICD widths can be achieved.} | ||||||
BibTeX:
@article{Jabbari14,
author = {Jabbari, G. and Klaiman, S. and Chiang, Y.-C. and Trinter, F. and Jahnke, T. and Gokhberg, K.},
title = {{Ab initio calculation of ICD widths in photoexcited HeNe}},
journal = {J. Chem. Phys.},
publisher = {AIP},
year = {2014},
volume = {140},
issue = {22},
pages = {224305},
numpages = {7},
note = {theory},
doi = {https://doi.org/10.1063/1.4881598}
}
|
||||||
| K. Gokhberg, P. Kolorenč, A.I. Kuleff & L.S. Cederbaum | Site- and energy-selective slow-electron production through intermolecular Coulombic decay | 2014 | Nature 505, 661 |
|||
| Abstract: {Irradiation of matter with light tends to electronically excite atoms and molecules, with subsequent relaxation processes determining where the photon energy is ultimately deposited and electrons and ions produced. In weakly bound systems, intermolecular Coulombic decay (ICD) enables very efficient relaxation of electronic excitation through transfer of the excess energy to neighbouring atoms or molecules that then lose an electron and become ionized. Here we propose that the emission site and energy of the electrons released during this process can be controlled by coupling the ICD to a resonant core excitation. We illustrate this concept with ab initio many-body calculations on the argon-krypton model system, where resonant photoabsorption produces an initial or 'parent' excitation of the argon atom, which then triggers a resonant-Auger-ICD cascade that ends with the emission of a slow electron from the krypton atom. Our calculations show that the energy of the emitted electrons depends sensitively on the initial excited state of the argon atom. The incident energy can thus be adjusted both to produce the initial excitation in a chosen atom and to realize an excitation that will result in the emission of ICD electrons with desired energies. These properties of the decay cascade might have consequences for fundamental and applied radiation biology and could be of interest in the development of new spectroscopic techniques.} | ||||||
BibTeX:
@article{Gokhberg14,
author = {Gokhberg, K. and Kolorenč, P. and Kuleff, A. I. and Cederbaum, L. S.},
title = {{Site- and energy-selective slow-electron production through intermolecular Coulombic decay}},
journal = {Nature},
publisher = {Nature Research},
year = {2014},
volume = {505},
issue = {7485},
pages = {661},
numpages = {3},
note = {theory},
doi = {https://doi.org/10.1038/nature12936}
}
|
||||||
| A. Ghosh & N. Vaval | Geometry-dependent lifetime of Interatomic coulombic decay using equation-of-motion coupled cluster method | 2014 | J. Chem. Phys. 141, 234108 |
|||
| Abstract: {Electronically excited atom or molecule in an environment can relax via transferring its excess energy to the neighboring atoms or molecules. The process is called Interatomic or Intermolecular coulombic decay (ICD). The ICD is a fast decay process in environment. Generally, the ICD mechanism predominates in weakly bound clusters. In this paper, we have applied the complex absorbing potential approach/equation-of-motion coupled cluster (CAP/EOMCCSD) method which is a combination of CAP and EOMCC approach to study the lifetime of ICD at various geometries of the molecules. We have applied this method to calculate the lifetime of ICD in Ne-X; X = Ne, Mg, Ar, systems. We compare our results with other theoretical and experimental results available in literature.} | ||||||
BibTeX:
@article{Ghosh14b,
author = {Ghosh, A. and Vaval, N.},
title = {{Geometry-dependent lifetime of Interatomic coulombic decay using equation-of-motion coupled cluster method}},
journal = {J. Chem. Phys.},
publisher = {AIP},
year = {2014},
volume = {141},
issue = {23},
pages = {234108},
numpages = {6},
note = {theory},
doi = {https://doi.org/10.1063/1.4903827}
}
|
||||||
| A. Ghosh, S. Pal & N. Vaval | Interatomic Coulombic decay in (HF)n (n=2-3) clusters using CAP/EOM-CCSD method | 2014 | Mol. Phys. 112, 669 |
|||
| Abstract: {The equation-of-motion coupled-cluster method along with the complex absorbing potential has been applied to study the interatomic Coulombic decay mechanism in hydrogen-bonded clusters. We have applied this method to calculate the lifetime of the F 2s inner-valence ionised state of (HF)n (n=2-3) clusters. The lifetime is found to be very short and decreases substantially with increasing the number of HF monomer.} | ||||||
BibTeX:
@article{Ghosh14a,
author = {Ghosh, A. and Pal, S. and Vaval, N.},
title = {{Interatomic Coulombic decay in (HF)n (n=2-3) clusters using CAP/EOM-CCSD method}},
journal = {Mol. Phys.},
publisher = {Taylor & Francis},
year = {2014},
volume = {112},
issue = {5-6},
pages = {669},
numpages = {5},
note = {theory},
doi = {https://doi.org/10.1080/00268976.2013.852263}
}
|
||||||
| S.I. Mondal, A. Dey, S. Sen, G.N. Patwari & D. Ghosh | Spectroscopic and ab initio investigation of 2,6-difluorophenylacetylene-amine complexes: coexistence of C-H...N and lone-pair...pi complexes and intermolecular coulombic decay | 2015 | Phys. Chem. Chem. Phys. 17, 434 |
|||
| Abstract: {Binary complexes of 2,6-difluorophenylacetylene with methylamine, dimethylamine, trimethylamine and triethylamine were investigated using one colour resonant two photon ionization and infrared-optical double resonance spectroscopic techniques combined with high level ab initio calculations. All four amines form CAc—H⋯N hydrogen-bonded complexes. Additionally trimethylamine and triethylamine form complexes characterized by Lp—π interactions, due to the electron deficient nature of the phenyl ring of 2,6-difluorophenylacetylene. The Lp—π interacting structure of the 2,6-difluorophenylacetylene-trimethylamine complex is about 1.5 kJ mol-1 higher in energy than the CAc—H⋯N hydrogen-bonded structure, which is the global minimum. Energy decomposition analysis indicates that the electrostatics and dispersion interactions favour the formation of CAc—H⋯N and Lp—π complexes, respectively. Interestingly the CAc—H⋯N hydrogen-bonded complex of 2,6-difluorophenylacetylene-triethylamine showed a smaller shift in the acetylenic C—H stretching frequency than the 2,6-difluorophenylacetylene-trimethylamine complex. The observed fragmentation of the binary complexes of 2,6-difluorophenylacetylene with the four amines following resonant two-photon ionization can be explained on the basis of the intermolecular coulombic decay process.} | ||||||
BibTeX:
@article{Mondal15,
author = {Mondal, S. I. and Dey, A. and Sen, S. and Patwari, G. N. and Ghosh, D.},
title = {{Spectroscopic and ab initio investigation of 2,6-difluorophenylacetylene-amine complexes: coexistence of C-H...N and lone-pair...pi complexes and intermolecular coulombic decay}},
journal = {Phys. Chem. Chem. Phys.},
publisher = {RSC},
year = {2015},
volume = {17},
issue = {1},
pages = {434},
numpages = {10},
note = {theory},
doi = {https://doi.org/10.1039/C4CP03445G}
}
|
||||||
| P. Kolorenč & N. Sisourat | Interatomic Coulombic decay widths of helium trimer: Ab initio calculations | 2015 | J. Chem. Phys. 143, 224310 |
|||
| Abstract: {We report on an extensive study of interatomic Coulombic decay (ICD) widths in helium trimer computed using a fully ab initio method based on the Fano theory of resonances. Algebraic diagrammatic construction for one-particle Green's function is utilized for the solution of the many-electron problem. An advanced and universal approach to partitioning of the configuration space into discrete states and continuum subspaces is described and employed. Total decay widths are presented for all ICD-active states of the trimer characterized by one-site ionization and additional excitation of an electron into the second shell. Selected partial decay widths are analyzed in detail, showing how three-body effects can qualitatively change the character of certain relaxation transitions. Previously unreported type of three-electron decay processes is identified in one class of the metastable states.} | ||||||
BibTeX:
@article{Kolorenc15,
author = {Kolorenč, P. and Sisourat, N.},
title = {{Interatomic Coulombic decay widths of helium trimer: Ab initio calculations}},
journal = {J. Chem. Phys.},
publisher = {AIP},
year = {2015},
volume = {143},
issue = {22},
pages = {224310},
numpages = {12},
note = {theory},
doi = {https://doi.org/10.1063/1.4936897}
}
|
||||||
| T. Goldzak, L. Gantz, I. Gilary, G. Bahir & N. Moiseyev | Interatomic Coulombic decay in two coupled quantum wells | 2015 | Phys. Rev. B 91, 165312 |
|||
| Abstract: {Interatomic Coulombic decay (ICD) is a relaxation process induced by electronic correlation. In this work we study the ICD process in a two coupled quantum wells (QWs) nanostructure. We study a simple one-dimensional effective potential using experimental parameters of the semiconductor QW layers, i.e., using the single-band effective-mass approximation. In our calculations we consider the discontinuity of the effective mass of the electron in each of the QW layers. We control the ICD lifetime by changing the distance between the two wells. The expected overall trend is a decrease of ICD lifetime with a decrease in the distance between the wells. We show that the distance can be tuned such that the emitted ICD electron is trapped in a metastable state in the con-tinuum, i.e., a one-electron resonance state. This causes the lifetime of the ICD to be an order of magnitude smaller even at very long distances, and improves the efficiency of the ICD process. For the ICD to be the dominant decay mechanism it must prevail over all other possible competitive decay processes. We have found that the lifetime of the ICD is on the time scale of picoseconds. Therefore, based on our results we can design an experiment that will observe the ICD phenomenon in QWs nanostructure. This work can lead to a design of a wavelength-sensitive detector which is efficient even at low intensities.} | ||||||
BibTeX:
@article{Goldzak15,
author = {Goldzak, T. and Gantz, L. and Gilary, I. and Bahir, G. and Moiseyev, N.},
title = {{Interatomic Coulombic decay in two coupled quantum wells}},
journal = {Phys. Rev. B},
publisher = {American Physical Society},
year = {2015},
volume = {91},
issue = {16},
pages = {165312},
numpages = {8},
note = {theory},
doi = {https://doi.org/10.1103/PhysRevB.91.165312}
}
|
||||||
| A. Bande, F.M. Pont, K. Gokhberg & L.S. Cederbaum | Interatomic Coulombic electron capture in atomic, molecular, and quantum dot systems | 2015 | Eur. Phys. J. Conf. 84, 07002 |
|||
| Abstract: {The interatomic Coulombic electron capture (ICEC) process has recently been predicted theoretically for clusters of atoms and molecules. For an atom A capturing an electron e(ε) it competes with the well known photorecombination, because in an environment of neutral or anionic neighboring atoms B, A can transfer its excess energy in the ultrafast ICEC process to B which is then ionized. The cross section for e(ε) + A + B → A- + B+ + e(ε´) has been obtained in an asymptotic approximation based on scattering theory for several clusters [1,2]. It was found that ICEC starts dominating the PR for distances among participating species of nanometers and lower. Therefore, we believe that the ICEC process might be of importance in the atmosphere, in biological systems, plasmas, or in nanostructured materials. As an example for the latter, ICEC has been investigated by means of electron dynamics in a model potential for semiconductor double quantum dots (QDs) [3]. In the simplest case one QD captures an electron while the outgoing electron is emitted from the other. The reaction probability for this process was found to be relatively large.} | ||||||
BibTeX:
@proceedings{Bande15,
author = {Bande, A. and Pont, F. M. and Gokhberg, K. and Cederbaum, L. S.},
title = {{Interatomic Coulombic electron capture in atomic, molecular, and quantum dot systems}},
journal = {Eur. Phys. J. Conf.},
series= {DR2013: Ninth International Conference on Dissociative Recombination: Theory, Experiment, and Applications},
publisher = {EDP Sciences},
year = {2015},
volume = {84},
pages = {07002},
numpages = {7},
note = {theory},
doi = {https://doi.org/10.1051/epjconf/20158407002}
}
|
||||||
| V. Stumpf, K. Gokhberg & L.S. Cederbaum | The role of metal ions in X-ray-induced photochemistry | 2016 | Nat. Chem. 8, 237 |
|||
| Abstract: {Metal centres in biomolecules are recognized as being particularly sensitive to radiation damage by X-ray photons. This results in such molecules being both susceptible to an effective X-ray-induced loss of function and problematic to study using X-ray diffraction methods, with reliable structures of the metal centres difficult to obtain. Despite the abundance of experimental evidence, the mechanistic details of radiation damage at metal centres are unclear. Here, using ab initio calculations, we show that the absorption of X-rays by microsolvated Mg2+ results in a complicated chain of ultrafast electronic relaxation steps that comprise both intra- and intermolecular processes and last for a few hundred femtoseconds. At the end of this cascade the metal reverts to its original charge state, the immediate environment becomes multiply ionized and large concentrations of radicals and slow electrons build up in the metal's vicinity. We conclude that such cascades involving metal ions are essential to our understanding of radiation chemistry and radiation damage in biological environments.} | ||||||
BibTeX:
@article{Stumpf16a,
author = {Stumpf, V. and Gokhberg, K. and Cederbaum, L. S.},
title = {{The role of metal ions in X-ray-induced photochemistry}},
journal = {Nat. Chem.},
publisher = {Nature Research},
year = {2016},
volume = {8},
pages = {237},
numpages = {5},
note = {theory},
doi = {https://doi.org/10.1038/nchem.2429}
}
|
||||||
| V. Stumpf, C. Brunken & K. Gokhberg | Impact of metal ion's charge on the interatomic Coulombic decay widths in microsolvated clusters | 2016 | J. Chem. Phys. 145, 104306 |
|||
| Abstract: {Interatomic Coulombic decay (ICD) is an efficient electronic decay mechanism of electronically excited atoms and molecules embedded in an environment. For the series of isoelectronic Na+, Mg2+, and Al3+ ions in aqueous solution, ultrashort ICD lifetimes of 3.1 fs, 1.5 fs, and 0.9 fs, respectively, were observed experimentally. The magnitude of the ICD lifetimes and their variation within the series were qualitatively explained by shortening metal-oxygen equilibrium distances and the increasing polarization of the water molecules as the metal's charge grows. We carried out an extensive ab initio investigation of the variation of the ICD widths with the metal-oxygen distances and the number of water neighbors in Na+-(H2O)m (m = 1-4) and Mg2+-(H2O)n (n = 1-6) clusters including and excluding polarization effects in the decaying state. We demonstrated that the effect of the induced polarization of the water ligand and the equilibrium cation-oxygen distance are equally important in determining the ordering and ratios of the ICD lifetimes in the series. Moreover, we showed that the induced polarization of the water molecules leads to a slower than linear growth of ICD width with the number of equivalent water neighbors; the non-linearity is stronger for Mg2+. The ab initio ICD widths in microsolvated Na+-(H2O)4 and Mg2+-(H2O)6 clusters are found to be in good agreement with the experimental values.} | ||||||
BibTeX:
@article{Stumpf16b,
author = {Stumpf, V. and Brunken, C. and Gokhberg, K.},
title = {{Impact of metal ion's charge on the interatomic Coulombic decay widths in microsolvated clusters}},
journal = {J. Chem. Phys.},
publisher = {AIP},
year = {2016},
volume = {145},
issue = {10},
pages = {104306},
numpages = {9},
note = {theory},
doi = {https://doi.org/10.1063/1.4962353}
}
|
||||||
| N. Sisourat, S. Kazandjian, A. Randimbiarisolo & P. Kolorenč | Interatomic Coulombic decay widths of helium trimer: A diatomics-in-molecules approach | 2016 | J. Chem. Phys. 144, 084111 |
|||
| Abstract: {We report a new method to compute the Interatomic Coulombic Decay (ICD) widths for large clusters which relies on the combination of the projection-operator formalism of scattering theory and the diatomics-in-molecules approach. The total and partial ICD widths of a cluster are computed from the energies and coupling matrix elements of the atomic and diatomic fragments of the system. The method is applied to the helium trimer and the results are compared to fully ab initio widths. A good agreement between the two sets of data is shown. Limitations of the present method are also discussed.} | ||||||
BibTeX:
@article{Sisourat16,
author = {Sisourat, N. and Kazandjian, S. and Randimbiarisolo, A. and Kolorenč, P.},
title = {{Interatomic Coulombic decay widths of helium trimer: A diatomics-in-molecules approach}},
journal = {J. Chem. Phys.},
publisher = {AIP},
year = {2016},
volume = {144},
issue = {8},
pages = {084111},
numpages = {7},
note = {theory},
doi = {https://doi.org/10.1063/1.4942483}
}
|
||||||
| F.M. Pont, A. Bande & L.S. Cederbaum | Electron-correlation driven capture and release in double quantum dots | 2016 | J. Phys.: Condens. Matter 28, 075301 |
|||
| Abstract: {We recently predicted that the interatomic Coulombic electron capture (ICEC) process, a long-range electron correlation driven capture process, is achievable in gated double quantum dots (DQDs). In ICEC an incoming electron is captured by one quantum dot (QD) and the excess energy is used to remove an electron from the neighboring QD. In this work we present systematic full three-dimensional electron dynamics calculations in quasi-one dimensional model potentials that allow for a detailed understanding of the connection between the DQD geometry and the reaction probability for the ICEC process. We derive an effective one-dimensional approach and show that its results compare very well with those obtained using the full three-dimensional calculations. This approach substantially reduces the computation times. The investigation of the electronic structure for various DQD geometries for which the ICEC process can take place clarify the origin of its remarkably high probability in the presence of two-electron resonances.} | ||||||
BibTeX:
@article{Pont16,
author = {Pont, F. M. and Bande, A. and Cederbaum, L. S.},
title = {{Electron-correlation driven capture and release in double quantum dots}},
journal = {J. Phys.: Condens. Matter},
publisher = {IOP},
year = {2016},
volume = {28},
issue = {7},
pages = {075301},
numpages = {15},
note = {theory},
doi = {https://doi.org/10.1088/0953-8984/28/7/075301}
}
|
||||||
| N.V. Kryzhevoi | Microhydration of LiOH: Insight from electronic decays of core-ionized states | 2016 | J. Chem. Phys. 144, 244302 |
|||
| Abstract: {We compute and compare the autoionization spectra of a core-ionized LiOH molecule both in its isolated and microhydrated states. Stepwise microhydration of LiOH leads to gradual elongation of the Li-OH bond length and finally to molecular dissociation. The accompanying changes in the local environment of the OH- and Li+ counterions are reflected in the computed O 1s and Li 1s spectra. The role of solvent water molecules and the counterion in the spectral shape formation is assessed. Electronic decays of the microhydrated LiOH are found to be mostly intermolecular since the majority of the populated final states have at least one outer-valence vacancy outside the initially core-ionized ion, mainly on a neighboring water molecule. The charge delocalization occurs through the intermolecular Coulombic and electron transfer mediated decays. Both mechanisms are highly efficient that is partly attributed to hybridization of molecular orbitals. The computed spectral shapes are sensitive to the counterion separation as well as to the number and arrangement of solvent molecules. These sensitivities can be used for studying the local hydration structure of solvated ions in aqueous solutions.} | ||||||
BibTeX:
@article{Kryzhevoi16,
author = {Kryzhevoi, N. V.},
title = {{Microhydration of LiOH: Insight from electronic decays of core-ionized states}},
journal = {J. Chem. Phys.},
publisher = {AIP},
year = {2016},
volume = {144},
issue = {24},
pages = {244302},
numpages = {7},
note = {theory},
doi = {https://doi.org/10.1063/1.4954661}
}
|
||||||
| G. Jabbari, K. Sadri, L.S. Cederbaum & K. Gokhberg | Strong enhancement of cage effects in water photolysis caused by interatomic Coulombic decay | 2016 | J. Chem. Phys. 144, 164307 |
|||
| Abstract: {The impact of the solvent on the photodissociation of embedded molecules has been intensively investigated in the last decades. Collisions of photofragments with the solvating atoms or molecules can change their kinetic energy distribution or even lead to the de-excitation of the dissociating molecule to a bound electronic state quenching the dissociation. In this article we show that this cage effect is strongly enhanced if interatomic Coulombic decay (ICD) of the excited state becomes allowed. Ab initio calculations in H2O–Cl- cluster show that the ultra-fast dissociation of water in the à excited state is strongly quenched by ICD. We found that this very efficient quenching is due to two factors. First, the lifetimes of the à state due to ICD are short ranging between 6 and 30 fs. Second, nuclear dynamics is dominated by the chattering motion of the H atom between O and Cl- allowing ICD to act for longer times. We hope that this work will be an important first step in clarifying the impact of ICD on photodissociation of embedded molecules.} | ||||||
BibTeX:
@article{Jabbari16,
author = {Jabbari, G. and Sadri, K. and Cederbaum, L. S. and Gokhberg, K.},
title = {{Strong enhancement of cage effects in water photolysis caused by interatomic Coulombic decay}},
journal = {J. Chem. Phys.},
publisher = {AIP},
year = {2016},
volume = {144},
issue = {16},
pages = {164307},
numpages = {8},
note = {theory},
doi = {https://doi.org/10.1063/1.4947238}
}
|
||||||
| T. Goldzak, L. Gantz, I. Gilary, G. Bahir & N. Moiseyev | Vertical currents due to interatomic Coulombic decay in experiments with two coupled quantum wells | 2016 | Phys. Rev. B 93, 045310 |
|||
| Abstract: {Interatomic Coulombic decay (ICD) is an ionization phenomena that takes place due to the Coulombic electronic repulsion force that correlates the ionized electrons with the other electrons. Here we present an analytical analysis of the ICD in two coupled quantum wells (QWs) which shows that the ICD ionization of an electron is in the perpendicular direction to the semiconductor layers. This happens when two conditions are satisfied. The first condition requires the excitation of the two electrons from the valence band. The first electron is excited to the bottom of the excited subband in one quantum well, and the second to the bottom of the first subband of the adjacent QW. The second condition ensures that the distance between the wells is large enough. In our case the two QWs are far apart when the distance between the two QWs is larger than 80 Å. Only vertical currents are expected in such a case. These conditions can be verified by future experiments.} | ||||||
BibTeX:
@article{Goldzak16,
author = {Goldzak, T. and Gantz, L. and Gilary, I. and Bahir, G. and Moiseyev, N.},
title = {{Vertical currents due to interatomic Coulombic decay in experiments with two coupled quantum wells}},
journal = {Phys. Rev. B},
publisher = {American Physical Society},
year = {2016},
volume = {93},
issue = {4},
pages = {045310},
numpages = {4},
note = {theory},
doi = {https://doi.org/10.1103/PhysRevB.93.045310}
}
|
||||||
| E. Fasshauer | Non-nearest neighbour ICD in clusters | 2016 | New J. Phys. 18, 043028 |
|||
| Abstract: {Interatomic Coulombic decay (ICD) is an electronic decay process of excited, ionized systems. It has been shown to occur in a multitude of small and large systems. The effects of more than one possible decay partner are discussed in detail illustrated by simulated ICD electron spectra of NeAr clusters and pure Ne clusters. Hereby, the mostly underestimated contribution of decay with non-nearest neighbours is highlighted. In the neon clusters, the lifetime of the bulk atoms is found to be in excellent agreement with experiment (Jahnke et al 2004 Phys. Rev. Lett. 93 173401) while the lifetimes of the surface atoms differ significantly. Hence, the experimental lifetime can not purely be explained by the effect of the number of neighbours. We propose the possibility to investigate the transition from small clusters to the solid state by using the ICD electron spectra to distinguish between icosahedral and cuboctahedral cluster structures.} | ||||||
BibTeX:
@article{Fasshauer16,
author = {Fasshauer, E.},
title = {{Non-nearest neighbour ICD in clusters}},
journal = {New J. Phys.},
publisher = {IOP},
year = {2016},
volume = {18},
issue = {4},
pages = {043028},
numpages = {10},
note = {theory},
doi = {https://doi.org/10.1088/1367-2630/18/4/043028}
}
|
||||||
| P. Dolbundalchok, D. Peláez, E.F. Aziz & A. Bande | Geometrical Control of the Interatomic Coulombic Decay Process in Quantum Dots for Infrared Photodetectors | 2016 | J. Comp. Chem. 37, 2249 |
|||
| Abstract: {In electron dynamics calculations the interatomic Coulombic decay (ICD) process has recently been shown to take place in two vertically-aligned quantum dots (QDs). Energy emitted during the relaxation of one electron in one QD is converted into kinetic energy of another electron ejected from a neighboring QD. As the electronic structure of QDs can be controlled by their geometries, we prove here in thorough scans of the transversal and vertical QD confinement potentials' widths that geometries are likewise control parameters for ICD. Such a comprehensive investigation has been enabled by a significant development of the calculations in terms of speed achieved among others by optimization of the grid and Coulomb interaction operator representations. As key result of this study we propose two cigar-shaped singly-charged GaAs QDs vertically aligned in the direction of their long side for a most efficient QD ICD realization useful for an infrared photodetector.} | ||||||
BibTeX:
@article{Dolbundalchok16,
author = {Dolbundalchok, P. and Peláez, D. and Aziz, E. F. and Bande, A.},
title = {{Geometrical Control of the Interatomic Coulombic Decay Process in Quantum Dots for Infrared Photodetectors}},
journal = {J. Comp. Chem.},
publisher = {Wiley-VCH},
year = {2016},
volume = {37},
issue = {25},
pages = {2249},
numpages = {11},
note = {theory},
doi = {https://doi.org/10.1002/jcc.24410}
}
|
||||||
| R.A. Wilhelm, E. Gruber, J. Schwestka, R. Kozubek, T.I. Madeira, J.P. Marques, J. Kobus, A.V. Krasheninnikov, M. Schleberger & F. Aumayr | Interatomic Coulombic Decay: The Mechanism for Rapid Deexcitation of Hollow Atoms | 2017 | Phys. Rev. Lett. 119, 103401 |
|||
| Abstract: {The impact of a highly charged ion onto a solid gives rise to charge exchange between the ion and target atoms, so that a slow ion gets neutralized in the vicinity of the surface. Using highly charged Ar and Xe ions and the surface-only material graphene as a target, we show that the neutralization and deexcitation of the ions proceeds on a sub-10 fs time scale. We further demonstrate that a multiple Interatomic Coulombic Decay (ICD) model can describe the observed ultrafast deexcitation. Other deexcitation mechanisms involving nonradiative decay and quasimolecular orbital formation during the impact are not important, as follows from the comparison of our experimental data with the results of first-principles calculations. Our method also enables the estimation of ICD rates directly.} | ||||||
BibTeX:
@article{Wilhelm17,
author = {Wilhelm, R. A. and Gruber, E. and Schwestka, J. and Kozubek, R. and Madeira, T. I. and Marques, J. P. and Kobus, J. and Krasheninnikov, A. V. and Schleberger, M. and and Aumayr, F.},
title = {{Interatomic Coulombic Decay: The Mechanism for Rapid Deexcitation of Hollow Atoms}},
journal = {Phys. Rev. Lett.},
publisher = {American Physical Society},
year = {2017},
volume = {119},
issue = {10},
pages = {103401},
numpages = {6},
note = {theory},
doi = {https://doi.org/10.1103/PhysRevLett.119.103401}
}
|
||||||
| F. Weber, E.F. Aziz & A. Bande | Interdependence of ICD rates in paired quantum dots on geometry | 2017 | J. Comp. Chem. 38, 2141 |
|||
| Abstract: {Using state-of-the-art antisymmetrized multiconfiguration time-dependent Hartree (MCTDH) electron dynamics calculations we study the interdependence of the intermolecular Coulombic decay (ICD) process on the geometric parameters of a doubly-charged paired quantum dot (PQD) model system in the framework of the effective mass approximation (EMA). We find that ICD displays a maximum rate for a certain geometry of the electron-emitting quantum dot, which is simultaneously dependent on both the distance between the quantum dots as well as the photon-absorbing quantum dot's geometry. The rate maximum is shown to be caused by the competing effects of polarization of electron density and Coulomb repulsion. The ICD rate-maximized PQD geometry in GaAs QDs yields a decay time of 102.39 ps. It is given by two vertically-aligned cylindrical QDs with radii of 14.42 nm separated by 86.62 nm. The photon absorbing QD then has a height of 46.59 nm and the electron emitting QD a height of 16.33 nm.} | ||||||
BibTeX:
@article{Weber17,
author = {Weber, F. and Aziz, E. F. and Bande, A.},
title = {{Interdependence of ICD rates in paired quantum dots on geometry}},
journal = {J. Comp. Chem.},
publisher = {Wiley-VCH},
year = {2017},
volume = {38},
pages = {2141},
numpages = {10},
note = {theory},
doi = {https://doi.org/10.1002/jcc.24843}
}
|
||||||
| V. Stumpf, S. Scheit, P. Kolorenč & K. Gokhberg | Electron transfer mediated decay in NeXe triggered by K-LL Auger decay of Ne | 2017 | Chem. Phys. 482, 192 |
|||
| Abstract: {In this article we present the results of an ab initio study of electron transfer mediated decay (ETMD) in NeXe dimer triggered by the K-LL Auger decay of Ne. We found that the Ne2+ (2p-2 1D)Xe and Ne2+(2p-2 1S)Xe states which are strongly populated in the Auger process may decay by ETMD emitting a slow electron and leading to the Coulomb explosion of the dimer which results in Ne+ and Xe2+ ions. We also computed the corresponding decay widths, the ETMD electron spectra, and the kinetic energy release of the nuclei (KER) spectra. We showed that the spectra corresponding to the decaying states which derive from the two multiplets have completely different shape which reflects differing accessibility of the ETMD final states. Thus, in the Ne2+ (2p-2 1S)Xe state ETMD is allowed for all interatomic distances accessible in nuclear dynamics, while in the Ne2+(2p-2 1D)Xe state the ETMD channels become closed one by one. This in turn leads to the different behavior of the ETMD decay widths and ultimately the spectra. We show how these differences make it possible to study ETMD of the two states separately in a coincident measurement. We also discuss how the dynamics which follow ETMD in the final state manifold may lead to the appearance of the unusual products: Ne, Xe3+ and a slow electron.} | ||||||
BibTeX:
@article{Stumpf17,
author = {Stumpf, V. and Scheit, S. and Kolorenč, P. and Gokhberg, K.},
title = {{Electron transfer mediated decay in NeXe triggered by K-LL Auger decay of Ne}},
journal = {Chem. Phys.},
publisher = {Elsevier},
year = {2017},
volume = {482},
pages = {192},
numpages = {9},
note = {theory},
doi = {https://doi.org/10.1016/j.chemphys.2016.08.018}
}
|
||||||
| N. Sisourat, S. Kazandjian & T. Miteva | Probing Conformers of Benzene Dimer with Intermolecular Coulombic Decay Spectroscopy | 2017 | J. Phys. Chem. A 121, 45 |
|||
| Abstract: {Benzene dimer is a prototype to study intermolecular interactions between aromatic systems. Owing to the weak interactions between the molecules within the dimer, several conformational geometries are nearly isoenergetic and thus coexist even at low temperatures. Furthermore, standard spectroscopies are unable to distinguish between them. In this work, we study the electronic relaxation processes following inner-valence ionization of benzene and the lowest conformers of benzene dimer. We show that the kinetic energy distributions of the secondary electrons emitted via two autoionization mechanisms, namely, the Auger and the intermolecular coulombic decay (ICD) effects, provide a means to probe the conformers of benzene dimer. The proposed spectroscopy opens the way to a better characterization of weakly bound molecular clusters.} | ||||||
BibTeX:
@article{Sisourat17a,
author = {Sisourat, N. and Kazandjian, S. and Miteva, T.},
title = {{Probing Conformers of Benzene Dimer with Intermolecular Coulombic Decay Spectroscopy}},
journal = {J. Phys. Chem. A},
publisher = {American Chemical Society},
year = {2017},
volume = {121},
issue = {1},
pages = {45},
numpages = {6},
note = {theory},
doi = {https://doi.org/10.1021/acs.jpca.6b09501}
}
|
||||||
| N. Sisourat, S. Engin, J.D. Gorfinkiel, S. Kazandjian, P. Kolorenč & T. Miteva | On the computations of interatomic Coulombic decay widths with R-matrix method | 2017 | J. Chem. Phys. 146, 244109 |
|||
| Abstract: {Interatomic Coulombic Decay (ICD) is a general mechanism in which an excited atom can transfer its excess energy to a neighbor which is thus ionized. ICD belongs to the family of Feshbach resonance processes, and, as such, states undergoing ICD are characterized by their energy width. In this work, we investigate the computations of ICD widths using the R-matrix method as implemented in the UKRmol package. Helium dimer is used here as a benchmark system. The results are compared with those obtained with the well established Fano-Algebraic Diagrammatic Construction method. It is shown that the R-matrix method in its present implementation provides accurate total and partial widths if the kinetic energy of the ICD electron is lower than 10 eV. Advantages and limitations of the R-matrix method on the computations of ICD widths are discussed.} | ||||||
BibTeX:
@article{Sisourat17b,
author = {Sisourat, N. and Engin, S. and Gorfinkiel, J. D. and Kazandjian, S. and Kolorenč, P. and Miteva, T.},
title = {{On the computations of interatomic Coulombic decay widths with R-matrix method}},
journal = {J. Chem. Phys.},
publisher = {AIP},
year = {2017},
volume = {146},
issue = {24},
pages = {244109},
numpages = {6},
note = {theory},
doi = {https://doi.org/10.1063/1.4989538}
}
|
||||||
| T. Miteva, S. Kazandjian & N. Sisourat | On the computations of decay widths of Fano resonances | 2017 | Chem. Phys. 482, 208 |
|||
| Abstract: {In this paper we present an ab initio approach to the computation of decay widths of Fano resonances. The method relies on Fano theory, in which a resonance is described as a bound state embedded in and interacting with a continuum of states. In our approach, we use the Configuration Interaction (CI) method to describe the bound-like and continuum-like parts of the resonance wave function. The aim of this Fano-CI method is to provide decay widths of resonances at a low computational cost such that large systems can be treated. Along with the implementation of the method, we present benchmark calculations of decay widths of Auger and ICD processes in Ne atom, and Ne2 and NeAr dimers. Our results are in good agreement with the decay widths from other theoretical and experimental works. This makes the Fano-CI approach a promising method for the treatment of Fano resonances.} | ||||||
BibTeX:
@article{Miteva17a,
author = {Miteva, T. and Kazandjian, S. and Sisourat, N.},
title = {{On the computations of decay widths of Fano resonances}},
journal = {Chem. Phys.},
publisher = {Elsevier},
year = {2017},
volume = {482},
pages = {208},
numpages = {8},
note = {theory},
doi = {https://doi.org/10.1016/j.chemphys.2016.08.014}
}
|
||||||
| T. Miteva, S. Kazandjian, P. Kolorenč, P. Votavová & N. Sisourat | Interatomic Coulombic Decay Mediated by Ultrafast Superexchange Energy Transfer | 2017 | Phys. Rev. Lett. 119, 083403 |
|||
| Abstract: {Inner-valence ionized states of atoms and molecules live shorter if these species are embedded in an environment due to the possibility for ultrafast deexcitation known as interatomic Coulombic decay (ICD). In this Letter we show that the lifetime of these ICD active states decreases further when a bridge atom is in proximity to the two interacting monomers. This novel mechanism, termed superexchange ICD, is an electronic correlation effect driven by the efficient energy transfer via virtual states of the bridge atom. The superexchange ICD is discussed in detail on the example of the NeHeNe trimer. We demonstrate that the decay width of the Ne+(2s-1)2Σ+g resonance increases 6 times in the presence of the He atom at a distance of 4 Å between the two Ne atoms. Using a simple model, we provide a qualitative explanation of the superexchange ICD and we derive analytical expressions for the dependence of the decay width on the distance between the neon atoms.} | ||||||
BibTeX:
@article{Miteva17b,
author = {Miteva, T. and Kazandjian, S. and Kolorenč, P. and Votavová, P. and Sisourat, N.},
title = {{Interatomic Coulombic Decay Mediated by Ultrafast Superexchange Energy Transfer}},
journal = {Phys. Rev. Lett.},
publisher = {American Physical Society},
year = {2017},
volume = {119},
issue = {8},
pages = {083403},
numpages = {5},
note = {theory},
doi = {https://doi.org/10.1103/PhysRevLett.119.083403}
}
|
||||||
| A.I. Kuleff | Electronic decay through carbon chains | 2017 | Chem. Phys. 482, 216 |
|||
| Abstract: {Using the multielectron wave-packet propagation method the electronic decay of O2s vacancy in fluorinated cumulenones, OCnF2, containing a chain of up to five carbons is traced in time and space. It is shown that in all studied cases this state decays non-locally by emitting an electron from the remote fluorines. Even in the pentatetraenone case, where the oxygen and the flourines are more than 7 Å apart, this non-local decay is extremely efficient, with a time constant of about 5 fs. The process can be viewed as an ultrafast energy transfer through the carbon chain and thus our systematic study allows to shed some light on the dependence of the time scale of the electron-correlation driven energy transfer through a medium.} | ||||||
BibTeX:
@article{Kuleff17,
author = {Kuleff, A. I.},
title = {{Electronic decay through carbon chains}},
journal = {Chem. Phys.},
publisher = {Elsevier},
year = {2017},
volume = {482},
pages = {216},
numpages = {5},
note = {theory},
doi = {https://doi.org/10.1016/j.chemphys.2016.09.007}
}
|
||||||
| A. Haller, Y.-C. Chiang, M. Menger, E.F. Aziz & A. Bande | Strong field control of the Interatomic Coulombic Decay process in quantum dots | 2017 | Chem. Phys. 482, 135 |
|||
| Abstract: {In recent years the laser-induced interatomic Coulombic decay (ICD) process in paired quantum dots has been predicted (Bande, 2013). In this work we target the enhancement of ICD by scanning over a range of strong-field laser intensities. The GaAs quantum dots are modeled by a one-dimensional double-well potential in which simulations are done with the space-resolved multi-configuration time-dependent Hartree method including antisymmetrization to account for the fermions. As a novelty a complementary state-resolved ansatz is developed to consolidate the interpretation of transient state populations, widths obtained for the ICD and the competing direct ionization channel, and Fano peak profiles in the photoelectron spectra. The major results are that multi-photon processes are unimportant even for the strongest fields. Further, below-π to π pulses display the highest ICD efficiency while the direct ionization becomes less dominant.} | ||||||
BibTeX:
@article{Haller17,
author = {Haller, A. and Chiang, Y.-C. and Menger, M. and Aziz, E. F. and Bande, A.},
title = {{Strong field control of the Interatomic Coulombic Decay process in quantum dots}},
journal = {Chem. Phys.},
publisher = {Elsevier},
year = {2017},
volume = {482},
pages = {135},
numpages = {11},
note = {theory},
doi = {https://doi.org/10.1016/j.chemphys.2016.09.020}
}
|
||||||
| N. Sisourat, T. Miteva, J.D. Gorfinkiel, K. Gokhberg & L.S. Cederbaum | Interatomic Coulombic electron capture from first principles | 2018 | Phys. Rev. A 98, 020701(R) |
|||
| Abstract: {Interatomic Coulombic electron capture (ICEC) is an environment-assisted process in which a free electron can efficiently attach to an ion, atom or molecule by transferring the excess energy to a neighboring species. Absolute cross sections are necessary to evaluate the relative importance of this process. In this work, we employ the R-matrix method to compute ab initio these cross sections for a singly charged neon ion embedded in small helium clusters. Our results show that the ICEC cross sections are several orders of magnitude higher than anticipated and dominate other competing processes. Electron energy loss spectra on an absolute scale are provided for the Ne+@He20 cluster. Such spectra exhibit an unambiguous signature of the ICEC process. The finding is expected to stimulate experimental observations.} | ||||||
BibTeX:
@article{Sisourat18,
author = {Sisourat, N. and Miteva, T. and Gorfinkiel, J. D. and Gokhberg, K. and Cederbaum, L. S.},
title = {{Interatomic Coulombic electron capture from first principles}},
journal = {Phys. Rev. A},
publisher = {American Physical Society},
year = {2018},
volume = {98},
issue = {2},
pages = {020701(R)},
numpages = {4},
note = {theory},
doi = {https://doi.org/10.1103/PhysRevA.98.020701}
}
|
||||||
| J.L. Hemmerich, R. Bennett & S.Y. Buhmann | The influence of retardation and dielectric environments on interatomic Coulombic decay | 2018 | Nat. Commun. 9, 2934 |
|||
| Abstract: {Interatomic Coulombic decay (ICD) is a very efficient process by which high-energy radiation is redistributed between molecular systems, often producing a slow electron, which can be damaging to biological tissue. During ICD, an initially-ionised and highly-excited donor species undergoes a transition where an outer-valence electron moves to a lower-lying vacancy, transmitting a photon with sufficient energy to ionise an acceptor species placed close by. Traditionally the ICD process has been described via ab initio quantum chemistry based on electrostatics in free space, which cannot include the effects of retardation stemming from the finite speed of light, nor the influence of a dispersive, absorbing, discontinuous environment. Here we develop a theoretical description of ICD based on macroscopic quantum electrodynamics in dielectrics, which fully incorporates all these effects, enabling the established power and broad applicability of macroscopic quantum electrodynamics to be unleashed across the fast-developing field of ICD.} | ||||||
BibTeX:
@article{Hemmerich18,
author = {Hemmerich, J. L. and Bennett, R. and Buhmann, S. Y.},
title = {{The influence of retardation and dielectric environments on interatomic Coulombic decay}},
journal = {Nat. Commun.},
publisher = {Nature Research},
year = {2018},
volume = {9},
pages = {2934},
numpages = {9},
note = {theory},
doi = {https://doi.org/10.1038/s41467-018-05091-x}
}
|
||||||
| A. Haller & A. Bande | Favoritism of quantum dot inter-Coulombic decay over direct and multi-photon ionization by laser strength and focus | 2018 | J. Chem. Phys. 149, 134102 |
|||
| Abstract: {We study the dynamics of a two-electron system undergoing resonant excitation and inter-Coulombic decay (ICD) in a pair of quantum dots. The influence of the focus of the exciting laser on the ICD process is investigated for a π-pulse with a close look on competing processes, i.e., direct ionization and multi-photon excitations. We scan through the field strength up to six Rabi cycles to show that ICD is still verifiable after several population inversions. With novel analyses, we determine for the first time populations of the different continuum states and thus conclude on the importance of several multi-photon excitation channels. Finally, we look into the influence of complex absorbing potentials on the dynamics.} | ||||||
BibTeX:
@article{Haller18,
author = {Haller, A. and Bande, A.},
title = {{Favoritism of quantum dot inter-Coulombic decay over direct and multi-photon ionization by laser strength and focus}},
journal = {J. Chem. Phys.},
publisher = {AIP},
year = {2018},
volume = {149},
issue = {13},
pages = {134102},
numpages = {12},
note = {theory},
doi = {https://doi.org/10.1063/1.5042208}
}
|
||||||
| J. Fedyk, A.B. Voitkiv & C. Müller | Strong-field photoionization in two-center atomic systems | 2018 | Phys. Rev. A 98, 033418 |
|||
| Abstract: {Photoionization of an atom A by a strong laser field in the presence of a spatially well-separated neighboring atom B is considered. The laser field frequency is assumed to lie below the ionization potential of atom A and be resonant with a dipole-allowed transition in atom B. In this situation, the ionization may occur either directly by multiphoton absorption from the laser field at the first atomic center or via an indirect pathway involving two-center electron-electron correlations, where the neighbor atom B is first photoexcited and, afterwards, transfers its energy upon deexcitation radiationlessly to atom A. Considering monochromatic as well as bichromatic laser fields, we study various coupling regimes of the photoionization process and identify experimentally accessible parameter domains where the two-center channel is dominant.} | ||||||
BibTeX:
@article{Fedyk18,
author = {Fedyk, J. and Voitkiv, A. B. and Müller, C.},
title = {{Strong-field photoionization in two-center atomic systems}},
journal = {Phys. Rev. A},
publisher = {American Physical Society},
year = {2018},
volume = {98},
issue = {3},
pages = {033418},
numpages = {9},
note = {theory},
doi = {https://doi.org/10.1103/PhysRevA.98.033418}
}
|
||||||
| A. Eckey, A. Jacob, A.B. Voitkiv & C. Müller | Resonant electron scattering and dielectronic recombination in two-center atomic systems | 2018 | Phys. Rev. A 98, 012710 |
|||
| Abstract: {Electron scattering and dielectronic recombination with an ion in the presence of a neighboring atom is studied. The incident electron is assumed to be captured by the ion, leading to resonant excitation of the atom which afterwards may stabilize either by electron reemission or radiative decay. We show that the participation of the atom can strongly affect, both quantitatively and qualitatively, the corresponding processes of electron scattering and recombination. Various ion-atom systems and electronic transitions are considered. In particular we show that electron scattering under backward angles may be strongly enhanced, provided the incident energy lies very close to the resonance. Besides, we derive the scaling behavior of two-center dielectronic recombination with the principal quantum numbers of the participating atomic states. The resonant enhancement in this process is shown to be so strong that it can compete with ordinary single-center recombination even after integrating over a rather broad distribution of incident electron energies.} | ||||||
BibTeX:
@article{Eckey18,
author = {Eckey, A. and Jacob, A. and Voitkiv, A. B. and Müller, C.},
title = {{Resonant electron scattering and dielectronic recombination in two-center atomic systems}},
journal = {Phys. Rev. A},
publisher = {American Physical Society},
year = {2018},
volume = {98},
pages = {012710},
numpages = {11},
note = {theory},
doi = {https://doi.org/10.1103/PhysRevA.98.012710}
}
|
||||||
| L.S. Cederbaum | Ultrafast Intermolecular Energy Transfer from Vibrations to Electronic Motion | 2018 | Phys. Rev. Lett. 121, 223001 |
|||
| Abstract: {It is discussed how vibrationally excited molecules in their electronic ground state can transfer their vibrational energy to the electronic motion of neighbors and ionize them. Based on explicit examples of vibrationally excited molecules and anionic neighbors, it is demonstrated that the transfer can be extremely efficient at intermolecular distances much beyond distances at which the molecule and its neighbor can form a bond.} | ||||||
BibTeX:
@article{Cederbaum18,
author = {Cederbaum, L. S.},
title = {{Ultrafast Intermolecular Energy Transfer from Vibrations to Electronic Motion}},
journal = {Phys. Rev. Lett.},
publisher = {American Physical Society},
year = {2018},
volume = {121},
issue = {22},
pages = {223001},
numpages = {6},
note = {theory},
doi = {https://doi.org/10.1103/PhysRevLett.121.223001}
}
|
||||||
| R.A. Wilhelm & P.L. Grande | Unraveling energy loss processes of low energy heavy ions in 2D materials | 2019 | Commun. Phys. 2, 89 |
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| Abstract: {Structuring of 2D materials and their heterostructures with ion beams is a challenging task, because typically low ion energies are needed to avoid damage to a substrate. In addition, at the very first monolayers of a material, ions are not yet in charge equilibrium, i.e. they may either charge up or neutralize depending on their velocity. The change in electronic structure of the ion during scattering affects the energy, which can be transferred to the recoil and therefore the energy available for defect formation. In order to make reliable use of ion beams for defect engineering of 2D materials, we present here a model for charge state and charge exchange dependent kinetic energy transfer. Our model can be applied to all ion species, ion charge states, and energies. It is especially powerful for predicting charge state dependent stopping of slow highly charged ions.} | ||||||
BibTeX:
@article{Wilhelml19,
author = {Wilhelm, R. A. and Grande, P. L.},
title = {{Unraveling energy loss processes of low energy heavy ions in 2D materials}},
journal = {Commun. Phys.},
publisher = {Nature Research},
year = {2019},
volume = {2},
pages = {89},
numpages = {8},
note = {theory},
doi = {https://doi.org/10.1038/s42005-019-0188-7}
}
|
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| P. Votavová, T. Miteva, S. Engin, S. Kazandjian, P. Kolorenč & N. Sisourat | Mechanism of superexchange interatomic Coulombic decay in rare-gas clusters | 2019 | Phys. Rev. A 100, 022706 |
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| Abstract: {Interatomic Coulombic decay (ICD) is an ultrafast energy transfer process. Via ICD, an excited atom can transfer its excess energy to a neighboring atom which is thus ionized. On the example of the NeHeNe cluster, we recently reported [Phys. Rev. Lett. 119, 083403 (2017)] that the total ICD widths are substantially enhanced in the presence of an ICD inactive atom. The enhancement occurs due to the coupling of the resonance state to intermediate virtual states of the bridge atom-a mechanism named superexchange ICD. In this followup work, we analyze the partial ICD widths in the NeHeNe cluster and show that only some channels are affected by the superexchange ICD process. Furthermore, we consider superexchange ICD in NeHeAr. We show that in this system the enhancement is still present but the energy transfer mediated by the superexchange mechanism is less efficient than in NeHeNe owing to the different ionization potentials of Ar and Ne. The behavior of the computed ICD widths is explained with a simple model based on first-order perturbation theory and a Hartree-Fock-like description of the states.} | ||||||
BibTeX:
@article{Votavova19,
author = {Votavová, P. and Miteva, T. and Engin, S. and Kazandjian, S. and Kolorenč, P. and Sisourat, N. },
title = {{Mechanism of superexchange interatomic Coulombic decay in rare-gas clusters}},
journal = {Phys. Rev. A},
publisher = {American Physical Society},
year = {2019},
volume = {100},
issue = {2},
pages = {022706},
numpages = {6},
note = {theory},
doi = {https://doi.org/10.1103/PhysRevA.100.022706}
}
|
||||||
| P. Raj & B. Pananghat | A balancing act of two electrons on a symmetric double-well barrier in a high frequency oscillating field | 2019 | Phys. Chem. Chem. Phys. 21, 3184 |
|||
| Abstract: {The dynamics of two electrons in a three-dimensional symmetric double-well quantum system is controlled using a high frequency oscillating electric field, achieving pairing of electrons and barrier-top localization. The field parameters of oscillating electric field intensity and frequency which are required to induce such an effect of barrier-top stabilization are easily estimated using time-independent Kramers-Henneberger electronic structure Full Configuration Interaction (FCI) calculations in an oscillating frame of reference with a Gaussian basis set. In the presence of the laser, the energy of the two-electron system in the symmetric double-well is found to be minimized when the barrier-top dynamic stabilization happens. Furthermore, the barrier-stabilized state finds importance in achieving a temporal control over electronic ionization. From approximate time-dependent calculations in the laboratory frame, the signatures of the barrier stabilized state are realized and it is observed that the paired-up state remains stable as long as the continuous wave region of the laser pulse is on. Ionization happens as soon as the laser pulse is switched off, because of the increased electronic repulsion in the paired up barrier-top state, thus giving a temporal control over laser-induced ionization.} | ||||||
BibTeX:
@article{Raj19,
author = {Raj, P. and Pananghat, B.},
title = {{A balancing act of two electrons on a symmetric double-well barrier in a high frequency oscillating field}},
journal = {Phys. Chem. Chem. Phys.},
publisher = {RSC},
year = {2019},
volume = {21},
pages = {3184},
numpages = {11},
note = {theory},
doi = {https://doi.org/10.1039/C8CP04812F}
}
|
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| F.M. Pont, A. Molle, E.R. Berikaa, S. Bubeck & A. Bande | Predicting the performance of the inter-coulombic electron capture from single-electron quantities | 2019 | J. Phys.: Condens. Matter 32, 065302 |
|||
| Abstract: {The probability of the inter-Coulombic electron capture (ICEC) is studied for nanowire-embedded quantum-dot pairs where electron capture in one dot leads to electron emission from the other. Previous studies pointed to an interdependence of several ICEC pathways which can enhance the ICEC reaction probability. To identify favorable criteria for such synergies in a qualitative and quantitative manner, we conducted a considerable amount of simulations scanning multiple geometrical parameters. The focus of the paper is not only to find the geometries which are most favorable to ICEC but most importantly to explain the basic principles of the ICEC probability. We have thus derived a number of energy relations among solely single-electron level energies that explain the mechanisms of the multiple reaction pathways. Among them are direct ICEC, both slowing or accelerating the outgoing electron, as well as resonance-enhanced ICEC which captures into a two-electron resonance state that decays thereafter. These pathways may apply simultaneously for just one single geometric configuration and contribute constructively leading to an enhancement of the reaction probability. Likewise some conditions are found that clearly turn down the ICEC probability to zero. The results based on single-electron relations are so general that they can as well be used to predict ICEC probability from the electronic structure in arbitrary physical systems such as atoms or molecules.} | ||||||
BibTeX:
@article{Pont19,
author = {Pont, F. M. and Molle, A. and Berikaa, E. R. and Bubeck, S. and Bande, A.},
title = {{Predicting the performance of the inter-coulombic electron capture from single-electron quantities}},
journal = {J. Phys.: Condens. Matter},
publisher = {IOP},
year = {2019},
volume = {32},
issue = {6},
pages = {065302},
numpages = {11},
note = {theory},
doi = {https://doi.org/10.1088/1361-648X/ab41a9}
}
|
||||||
| A. Molle, E.R. Berikaa, F.M. Pont & A. Bande | Quantum size effect affecting environment assisted electron capture in quantum confinements | 2019 | J. Chem. Phys. 150, 224105 |
|||
| Abstract: {Ultrafast inter-Coulombic electron capture (ICEC) has been established as an important energy-transfer process in open paired-quantum-dot systems which can mediate between entrapment of free-moving electrons and release of trapped ones elsewhere by long-range electron-electron interaction within nanowires. Previous studies indicated ICEC enhancement through population and secondary decay of two-center resonance states, the latter known as inter-Coulombic decay (ICD). This study investigates the quantum-size effect of single- and double-electron states in an established model of a quasi-one-dimensional nanowire with two embedded confinement sites, represented by a pair of Gaussian wells. We analyze the ICEC related electron flux density as a function of confinement size and are able to clearly identify two distinct capture channels: a direct long-range electron-electron impulse and a conversion of kinetic energy to electron-electron correlation energy with consecutive ICD. The overlay of both channels makes ICEC extremely likely, while nanowires are a strong candidate for the next miniaturization step of integrated-circuit components.} | ||||||
BibTeX:
@article{Molle19,
author = {Molle, A. and Berikaa, E. R. and Pont, F. M. and Bande, A.},
title = {{Quantum size effect affecting environment assisted electron capture in quantum confinements}},
journal = {J. Chem. Phys.},
publisher = {AIP},
year = {2019},
volume = {150},
issue = {22},
pages = {224105},
numpages = {14},
note = {theory},
doi = {https://doi.org/10.1063/1.5095999}
}
|
||||||
| F. Langkabel, M. Lützner & A. Bande | Interparticle Coulombic Decay Dynamics along Single- and Double-Ionization Pathways | 2019 | J. Phys. Chem. C 123, 21757 |
|||
| Abstract: {The interparticle Coulombic decay process (ICD) in a Coulomb-coupled pair of quantum dots (QDs) was predicted to feature electronic relaxation within one QD in conjunction with ionization of the other. In this work the QD model is extended from a pair to a triad of one excited and two ionizable QDs and in total three electrons. Analytical Wigner-Weisskopf expressions for the decay rates are formulated and confirmed with numerical electron dynamics calculations, suggesting a rate enhancement by a factor two that may be relevant for the competitiveness of ICD in QDs. Particularly, we compare two energetic scenarios, one allowing only for single ionization of the QD triad and one not yet discussed in the community, potentially allowing for double ionization.} | ||||||
BibTeX:
@article{Langkabel19,
author = {Langkabel, F. and Lützner, M. and Bande, A.},
title = {{Interparticle Coulombic Decay Dynamics along Single- and Double-Ionization Pathways}},
journal = {J. Phys. Chem. C},
publisher = {American Chemical Society},
year = {2019},
volume = {123},
issue = {35},
pages = {21757},
numpages = {6},
note = {theory},
doi = {https://doi.org/10.1021/acs.jpcc.9b04452}
}
|
||||||
| G.A. Jones & D.S. Bradshaw | Resonance Energy Transfer: From Fundamental Theory to Recent Applications | 2019 | Front. Phys. 7, 100 |
|||
| Abstract: {Resonance energy transfer (RET), the transport of electronic energy from one atom or molecule to another, has significant importance to a number of diverse areas of science. Since the pioneering experiments on RET by Cario and Franck in 1922, the theoretical understanding of the process has been continually refined. This review presents a historical account of the post-Förster outlook on RET, based on quantum electrodynamics, up to the present-day viewpoint. It is through this quantum framework that the short-range, R-6 distance dependence of Förster theory was unified with the long-range, radiative transfer governed by the inverse-square law. Crucial to the theoretical knowledge of RET is the electric dipole-electric dipole coupling tensor; we outline its mathematical derivation with a view to explaining some key physical concepts of RET. The higher order interactions that involve magnetic dipoles and electric quadrupoles are also discussed. To conclude, a survey is provided on the latest research, which includes transfer between nanomaterials, enhancement due to surface plasmons, possibilities outside the usual ultraviolet or visible range and RET within a cavity.} | ||||||
BibTeX:
@article{Jones19,
author = {Jones, G. A. and Bradshaw, D. S.},
title = {{Resonance Energy Transfer: From Fundamental Theory to Recent Applications}},
journal = {Front. Phys.},
publisher = {Frontiers},
year = {2019},
volume = {7},
pages = {100},
numpages = {19},
note = {theory},
doi = {https://doi.org/10.3389/fphy.2019.00100}
}
|
||||||
| Q. Jing & L.B. Madsen | Dynamics of interatomic Coulombic decay in neon dimers by XUV-pump-XUV-probe spectroscopy | 2019 | Phys. Rev. A 99, 013409 |
|||
| Abstract: {We apply the Monte Carlo wave-packet approach to study the interatomic Coulombic decay (ICD) dynamics of neon dimers after removing a 2s electron from one of the Ne atoms by one-photon absorption from an XUV pulse. This method reproduces well both the lifetime for the 2s inner-valence vacancy in Ne2+(2s-1) and the kinetic energy release (KER) spectra for the coincident Ne+ and Ne2+ fragments following triple ionization, i.e., two photoionizations and one ionization via ICD, of Ne2 measured in an XUV-pump-XUV-probe experiment [K. Schnorr et al., Phys. Rev. Lett. 111, 093402 (2013)]. Comparisons between the calculated and measured nuclear KER spectra give physical insights in the considered process. For example, an analysis of the ratios between the low- and high-energy peaks in the nuclear KER spectra for large delays provides an estimate of the photoionization cross sections for removing a 2p electron from the excited states in Ne2+(2s-1). Such comparisons also allow an estimate for the ICD rates for the 2s inner-valence vacancy in the single-site two hole state in Ne22+(2s-12p-1). Finally, the influence of photon statistics of the free electron laser pulses on the nuclear KER spectra is considered.} | ||||||
BibTeX:
@article{Jing19,
author = {Jing, Q. and Madsen, L. B.},
title = {{Dynamics of interatomic Coulombic decay in neon dimers by XUV-pump-XUV-probe spectroscopy}},
journal = {Phys. Rev. A},
publisher = {American Physical Society},
year = {2019},
volume = {99},
issue = {1},
pages = {013409},
numpages = {9},
note = {theory},
doi = {https://doi.org/10.1103/PhysRevA.99.013409}
}
|
||||||
| A. Jacob, C. Müller & A.B. Voitkiv | Two-center dielectronic recombination in slow atomic collisions | 2019 | Phys. Rev. A 100, 012706 |
|||
| Abstract: {A free electron can form a bound state with an atomic center A upon photoemission (radiative recombination). In the presence of a neighboring atom B, such a bound state can, under certain conditions, be also formed via resonant transfer of energy to B, with its subsequent relaxation through radiative decay (two-center dielectronic recombination). This two-center process is very efficient in the “static” case where A and B form a weakly bound system, dominating over single-center radiative recombination up to internuclear distances as large as several nanometers. Here we study its dynamic variant in which recombination occurs when a beam of species A collides with a gas of atoms B and show that, even though the average distance between A and B in collisions is orders of magnitude larger than the typical size of a bound system, the two-center recombination can still outperform the single-center radiative recombination.} | ||||||
BibTeX:
@article{Jacob19,
author = {Jacob, A. and Müller, C. and Voitkiv, A. B. },
title = {{Two-center dielectronic recombination in slow atomic collisions}},
journal = {Phys. Rev. A},
publisher = {American Physical Society},
year = {2019},
volume = {100},
issue = {1},
pages = {012706},
numpages = {8},
note = {theory},
doi = {https://doi.org/10.1103/PhysRevA.100.012706}
}
|
||||||
| A. Jacob, C. Müller & A.B. Voitkiv | Interatomic coulombic electron capture in slow atomic collisions | 2019 | J. Phys. B: At. Mol. Opt. Phys. 52, 225201 |
|||
| Abstract: {In the process of radiative recombination (RR)/attachment the capture of a free electron by an atomic species A proceeds via photoemission. In the so called interatomic coulombic electron capture, a capture of a free electron by A proceeds via its interaction with a neighboring species B that results in electron emission from the latter. This process can outperform RR/attachment when A and B form a (weakly) bound system. Here we consider this process in slow collisions between A and B and show that also in this dynamical situation it can successfully compete with RR/attachment if the density of species B is sufficiently large.} | ||||||
BibTeX:
@article{Jacob19b,
author = {Jacob, A. and Müller, C. and Voitkiv, A. B.},
title = {{Interatomic coulombic electron capture in slow atomic collisions}},
journal = {J. Phys. B: At. Mol. Opt. Phys.},
publisher = {IOP},
year = {2019},
volume = {52},
issue = {22},
pages = {225201},
numpages = {6},
note = {theory},
doi = {https://doi.org/10.1088/1361-6455/ab46ef}
}
|
||||||
| A. Haller, D. Peláez & A. Bande | Inter-Coulombic Decay in Laterally Arranged Quantum Dots Controlled by Polarized Lasers | 2019 | J. Phys. Chem. C 123, 14754 |
|||
| Abstract: {The inter-Coulombic decay (ICD) process, where one electronically excited species relaxes while the neighboring one is concomitantly ionized, has been recently discovered likewise in atomic, molecular, biological, and nanostructured systems. Any theoretical prediction of it relies strongly on an accurate treatment of the involved resonance and continuum states. Here, we describe laser-induced ICD in quantum dots with electron dynamics at a multiconfiguration time-dependent Hartree-Fock level for the first time for a two-dimensional continuum, such that ICD control with laser polarization is within reach. This explicit electron dynamics is possible through the efficient Multigrid POTFIT tensor decomposition of the Coulomb interaction on a grid. Conclusively, ICD turns out to be much faster in laterally arranged self-assembled or lithographic quantum dots connected to a two-dimensional wetting-layer continuum than in previously investigated dots in nanowires.} | ||||||
BibTeX:
@article{Haller19,
author = {Haller, A. and Peláez, D. and Bande, A.},
title = {{Inter-Coulombic Decay in Laterally Arranged Quantum Dots Controlled by Polarized Lasers}},
journal = {J. Phys. Chem. C},
publisher = {American Chemical Society},
year = {2019},
volume = {123},
issue = {23},
pages = {14754},
numpages = {12},
note = {theory},
doi = {https://doi.org/10.1021/acs.jpcc.9b01250}
}
|
||||||
| A. Grüll, A.B. Voitkiv & C. Müller | Two-center electron-impact ionization via collisional excitation-autoionization | 2019 | Phys. Rev. A 100, 032702 |
|||
| Abstract: {Electron-impact ionization of an atom or ion in the presence of a neighboring atom is studied. The latter is first collisionally excited by the incident electron, whose energy is assumed to be high but nonrelativistic. Afterwards, the excitation energy is transferred radiationlessly via a two-center Auger process to the other atom or ion, leading to its ionization. We show that the participation of the neighboring atom manifests in a very pronounced resonance peak in the energy-differential cross section and can substantially enhance the total cross section of electron-impact ionization. We also discuss the influence of the neighboring atom on the angular distribution of the ejected electron.} | ||||||
BibTeX:
@article{Gruell19,
author = {Grüll, A. and Voitkiv, A. B. and Müller, C. },
title = {{Two-center electron-impact ionization via collisional excitation-autoionization}},
journal = {Phys. Rev. A},
publisher = {American Physical Society},
year = {2019},
volume = {100},
issue = {3},
pages = {032702},
numpages = {8},
note = {theory},
doi = {https://doi.org/10.1103/PhysRevA.100.032702}
}
|
||||||
| T. Goldzak | Partial widths and branching ratios for the emitted electron resulting from interatomic Coulombic decay in quantum wells heterostructure | 2019 | Mol. Phys. 117, 2179 |
|||
| Abstract: {Interatomic coulomb decay (ICD) is a decay process relying on the Coulombic interaction between neighbouring atoms, molecules or nanostructures. Due to this process, an electron is emitted into the continuum. We study the ICD process in a system of the double quantum well heterostructure and investigate how we can manipulate the structure's parameters such that a better detection of the ICD's emitted electron is achieved. For this purpose, we calculated the partial widths (PWs) and branching ratios (BRs) of the ICD's emitted electron to the left and right asymptotes of the heterostructure; these will give an estimation of the detection current. We manipulated the structure's parameters and took into account the repulsion from the electron in the ground state located in the left well. By introducing two small barriers in the vicinity of the right QW, we observed a BR three times larger than in the structure without the barriers. We also investigate the effect of repulsion due to the second electron. This work gives a better understanding of the dynamics of the scattered ICD's electron, and realisation of better design rules for future experimental observation of ICD in nanostructures.} | ||||||
BibTeX:
@article{Goldzak19,
author = {Goldzak, T.},
title = {{Partial widths and branching ratios for the emitted electron resulting from interatomic Coulombic decay in quantum wells heterostructure}},
journal = {Mol. Phys.},
publisher = {Taylor & Francis},
year = {2019},
volume = {117},
pages = {2179},
numpages = {9},
note = {theory},
doi = {https://doi.org/10.1080/00268976.2019.1618507}
}
|
||||||
| A. Ghosh, L.S. Cederbaum & K. Gokhberg | Electron transfer mediated decay in HeLi2 cluster: Potential energy surfaces and decay widths | 2019 | J. Chem. Phys. 150, 164309 |
|||
| Abstract: {Electron transfer mediated decay (ETMD) is a process responsible for double ionization of dopants in He droplets. It is initiated by producing He+ in the droplet, which is neutralized by ETMD, and has been shown to strongly enhance the dopant's double ionization cross section. The efficiency of ETMD, the spectra of emitted secondary electrons, and the character of the ionic products depend on the nuclear dynamics during the decay. To date, there has been no theoretical investigation of multimode dynamics which accompanies ETMD, which could help to understand such dynamics in a He droplet. In this article, we consider the He–Li2 cluster where an ab initio examination of multimode dynamics during the electronic decay is feasible. Moreover, this cluster can serve as a minimal model for Li2 adsorbed on the droplet's surface — a system where ETMD can be observed experimentally. In He droplets, Li2 can be formed in both the ground X1Σ+g and the first excited a3Σ+u states. In this article, we present ab initio potential energy surfaces of the electronic states of the He–Li2 cluster involved in ETMD, as well as the respective decay widths. We show that the structure of these surfaces and expected nuclear dynamics strongly depend on the electronic state of Li2. Thus, the overall decay rate and the appearance of the observable electron spectra will be dictated by the electronic structure of the dopant.} | ||||||
BibTeX:
@article{Ghosh19,
author = {Ghosh, A. and Cederbaum, L. S. and Gokhberg, K.},
title = {{Electron transfer mediated decay in HeLi2 cluster: Potential energy surfaces and decay widths}},
journal = {J. Chem. Phys.},
publisher = {AIP},
year = {2019},
volume = {150},
issue = {16},
pages = {164309},
numpages = {12},
note = {theory},
doi = {https://doi.org/10.1063/1.5082952}
}
|
||||||
| Y.-C. Chiang, S. Engin, P. Bao, F. Otto, P. Kolorenč, P. Votavová, T. Miteva, J. Gao & N. Sisourat | Molecular-bond breaking induced by interatomic decay processes | 2019 | Phys. Rev. A 100, 052701 |
|||
| Abstract: {Selective bond breaking in a molecule with the use of photons opens the way to control chemical reactions. We demonstrate here that dissociation of a molecule can be efficiently achieved by first photoexciting a neighboring atom or molecule. On the example of the giant He-H2 dimer, we show that simultaneous ionization and excitation of the helium atom induces H2 dissociation with a high probability. The excited He+ ion transfers its excess energy via interatomic Coulombic decay (ICD) or electron transfer mediated decay (ETMD) to H2 which is then singly or doubly ionized, respectively. In both cases, the molecular ion dissociates effectively within a few tens of femtoseconds. Molecular-bond breaking induced by ICD and ETMD are expected to be general phenomena, which provide alternatives to standard photochemistry.} | ||||||
BibTeX:
@article{Chiang19,
author = {Chiang, Y.-C. and Engin, S. and Bao, P. and Otto, F. and Kolorenč, P. and Votavová, P. and Miteva, T. and Gao, J. and Sisourat, N.},
title = {{Molecular-bond breaking induced by interatomic decay processes}},
journal = {Phys. Rev. A},
publisher = {American Physical Society},
year = {2019},
volume = {100},
issue = {5},
pages = {052701},
numpages = {9},
note = {theory},
doi = {https://doi.org/10.1103/PhysRevA.100.052701}
}
|
||||||
| M. Berg, L. Uranga-Piña, A. Martínez-Mesa & A. Bande | Wavepacket golden rule treatment of interparticle Coulombic decay in paired quantum dots | 2019 | J. Chem. Phys. 151, 244111 |
|||
| Abstract: {The interparticle Coulombic decay process in paired quantum dots is studied by electron dynamics calculations. We consider a pair of Coulomb-coupled one-electron charged gallium arsenide quantum dots embedded in a nanowire. The two-electron decay process is approximately described by a single active electron model. Within this model, we employ the time-dependent wavepacket approach to the Fermi golden rule (introduced in the context of vibrational predissociation) to calculate autoionization rates, which are compared to exact rates obtained from fully correlated two-electron dynamics calculations. We found that the approximate decay rates agree well with the exact results in the limit of sufficiently separated quantum dots. Finally, we explore whether the short-range behavior of the new model can be further enhanced by the inclusion of local exchange effects by means of regularization of the Coulomb-potential based on a Jastrow-Slater wavefunction. The proposed method may open a route to study the interparticle Coulombic decay in more intricate systems, e.g., paired metal-nanoparticle-quantum dot systems.} | ||||||
BibTeX:
@article{Berg19,
author = {Berg, M. and Uranga-Piña, L. and Martínez-Mesa, A. and Bande, A.},
title = {{Wavepacket golden rule treatment of interparticle Coulombic decay in paired quantum dots}},
journal = {J. Chem. Phys.},
publisher = {AIP},
year = {2019},
volume = {151},
issue = {24},
pages = {244111},
numpages = {12},
note = {theory},
doi = {https://doi.org/10.1063/1.5131849}
}
|
||||||
| R. Bennett, P. Votavová, P. Kolorenč, T. Miteva, N. Sisourat & S.Y. Buhmann | Virtual Photon Approximation for Three-Body Interatomic Coulombic Decay | 2019 | Phys. Rev. Lett. 122, 153401 |
|||
| Abstract: {Interatomic Coulombic decay (ICD) is a mechanism that allows microscopic objects to rapidly exchange energy. When the two objects are distant, the energy transfer between the donor and acceptor species takes place via the exchange of a virtual photon. On the contrary, recent ab initio calculations have revealed that the presence of a third passive species can significantly enhance the ICD rate at short distances due to the effects of electronic wave function overlap and charge transfer states [Phys. Rev. Lett. 119, 083403 (2017)]. Here, we develop a virtual photon description of three-body ICD, allowing us to investigate retardation and geometrical effects which are out of reach for current ab initio techniques. We show that a passive atom can have a significant influence on the rate of the ICD process at fairly large interatomic distances, due to the scattering of virtual photons off the mediator. Moreover, we demonstrate that in the retarded regime ICD can be substantially enhanced or suppressed depending on the position of the ICD-inactive object, even if the latter is far from both donor and acceptor species.} | ||||||
BibTeX:
@article{Bennett19,
author = {Bennett, R. and Votavová, P. and Kolorenč, P. and Miteva, T. and Sisourat, N. and Buhmann, S. Y.},
title = {{Virtual Photon Approximation for Three-Body Interatomic Coulombic Decay}},
journal = {Phys. Rev. Lett.},
publisher = {American Physical Society},
year = {2019},
volume = {122},
issue = {15},
pages = {153401},
numpages = {6},
note = {theory},
doi = {https://doi.org/10.1103/PhysRevLett.122.153401}
}
|
||||||
| A. Bande | Acoustic phonon impact on the inter-Coulombic decay process in charged quantum dot pairs | 2019 | Mol. Phys. 117, 2014 |
|||
| Abstract: {Recently, highly accurate multi-configuration time-dependent Hartree electron dynamics calculations demonstrated the efficient long-range energy transfer inter-Coulombic decay (ICD) process to happen in charged semiconductor quantum dot (QD) pairs. ICD is initiated by intraband photoexcitation of one of the QDs and leads to electron emission from the other within a duration of about 150 ps. On the same time scale electronically excited states are reported to relax due to the coupling of electrons to acoustic phonons. Likewise, phonons promote ionisation. Here, the QDs' acoustic breathing mode is implemented in a frozen-phonon approach. A detailed comparison of the phonon effects on electron relaxation and emission as well as on the full ICD process is presented, which supports the previous empirical finding of ICD being the dominant decay channel in paired QDs. In addition the relative importance of phonon-phonon, phonon-electron and electron-electron interaction is analysed.} | ||||||
BibTeX:
@article{Bande19,
author = {Bande, A.},
title = {{Acoustic phonon impact on the inter-Coulombic decay process in charged quantum dot pairs}},
journal = {Mol. Phys.},
publisher = {Taylor & Francis},
year = {2019},
volume = {117},
pages = {2014},
numpages = {15},
note = {theory},
doi = {https://doi.org/10.1080/00268976.2019.1574986}
}
|
||||||
| J.B. Mullenix, V. Despré & A.I. Kuleff | Electronic decay through non-linear carbon chains | 2020 | J. Phys. B: At. Mol. Opt. Phys. 53, 184006 |
|||
| Abstract: {A multielectron wave-packet propagation method was used to calculate the electronic decay of oxygen and fluorine 2s vacancies for a group of trifluoroalkyl alcohols, HOCnH(2n-1)F3, with n between 1 and 5. Whether ionizing O2s or F2s orbitals, it is shown that an electron can be emitted non-locally from the opposite terminus of the molecule. The decay of the O(2s-1) state is found to be about 2–3 times faster than that of the F(2s-1), but in both cases the process takes only a few femtoseconds, demonstrating a highly efficient energy transfer through the carbon bridge. A comparison to the previously reported non-local decay in linear difluorocumulenone systems shows that the non-linearity of the trifluoroalkyl alcohols does not appear to dramatically influence the decay efficiency. These results shed light onto the nature of the scaling of electron correlation and open the door to the potential design of molecules that take advantage of this mechanism.} | ||||||
BibTeX:
@article{Mullenix20,
author = {Mullenix, J. B. and Despré, V. and Kuleff, A. I.},
title = {{Electronic decay through non-linear carbon chains}},
journal = {J. Phys. B: At. Mol. Opt. Phys.},
publisher = {IOP},
year = {2020},
volume = {53},
issue = {18},
pages = {184006},
numpages = {8},
note = {theory},
doi = {https://doi.org/10.1088/1361-6455/aba1ca}
}
|
||||||
| L. Liu, P. Kolorenč & K. Gokhberg | Efficiency of core-level interatomic Coulombic decay in rare-gas dimers | 2020 | Phys. Rev. A 101, 033402 |
|||
| Abstract: {In this work we investigated the competition between the local Auger decay and core-level interatomic Coulombic decay (ICD) processes in core ionized rare-gas dimers. We computed the respective partial decay widths for the 4d vacancy in Xe2, XeKr, and XeAr, as well as for the 3d vacancy in Kr2. We found that the efficiency of ICD is strongly increased with decreasing interatomic distance and decreasing energy transfer in the decay step. The ICD-to-Auger ratio in the Franck-Condon region, where the decay occurs, is at most 0.26%. However, it reaches a few percentage points in larger clusters and becomes amenable for experimental observation. The small value of the branching ratio is due to large interatomic distances in the dimers (4-4.4 Å). Our results also indicate, in accordance with previous measurements, that in hydrogen-bonded and microsolvated clusters, where the distances between the monomers are 2-3 Å, core-level ICD should become an important pathway for charge redistribution following the absorption of hard x-rays.} | ||||||
BibTeX:
@article{Liu20,
author = {Liu, L. and Kolorenč, P. and Gokhberg, K.},
title = {{Efficiency of core-level interatomic Coulombic decay in rare-gas dimers}},
journal = {Phys. Rev. A},
publisher = {American Physical Society},
year = {2020},
volume = {101},
issue = {3},
pages = {033402},
numpages = {10},
note = {theory},
doi = {https://doi.org/10.1103/PhysRevA.101.033402}
}
|
||||||
| A. Landau, A. Ben-Asher, K. Gokhberg, L.S. Cederbaum & N. Moiseyev | Ab initio complex potential energy curves of the He*(1s2p 1P)-Li dimer | 2020 | J. Chem. Phys. 152, 184303 |
|||
| Abstract: {LiHe is an intriguing open-shell dimer. It is an extremely weakly bound system, and its vibrational bound-state radius extends far into the classically forbidden regions. Exciting helium into 1s2p leads to a 2Σ and a 2Π state, in which lithium is in its ground state. These states are located above the ionization threshold of the Li atom, which makes them metastable, i.e., resonance states. Under these conditions, energy transfer between the atoms over large distances is feasible within the framework of interatomic Coulombic decay (ICD). These states are investigated theoretically; herein, we present and analyze the complex potential energy curves of the 2Σ and 2Π states, where their imaginary parts describe the decay rate of these resonance states. We employ the resonance via Padé approach to calculate these potentials. Thereby, we use the equation-of-motion coupled-cluster method to compute stabilization graphs as input data for the analytical dilation (via Padé) into the complex energy plane. The procedure is suitable for studying Feshbach resonances and ICD states such as the LiHe 2Σ and 2Π states. The resulting ab initio complex potential energy curves will be used in future work to describe the dynamics of the process HeLi + hν → He*Li → HeLi+ + eICD, which is amenable to experiment.} | ||||||
BibTeX:
@article{Landau20,
author = {Landau, A. and Ben-Asher, A. and Gokhberg, K. and Cederbaum, L. S. and Moiseyev, N.},
title = {{Ab initio complex potential energy curves of the He*(1s2p 1P)-Li dimer}},
journal = {J. Chem. Phys.},
publisher = {AIP},
year = {2020},
volume = {152},
issue = {16},
pages = {184303},
numpages = {8},
note = {theory},
doi = {https://doi.org/10.1063/5.0008337}
}
|
||||||
| P. Kolorenč & V. Averbukh | Fano-ADC(2,2) method for electronic decay rates | 2020 | J. Chem. Phys. 152, 214107 |
|||
| Abstract: {Fano-ADC is a family of ab initio methods for the prediction of electronic decay widths in excited, singly and doubly ionized systems. It has been particularly successful in elucidating the geometry dependence of the inter-atomic decay widths in clusters and facilitated the prediction of new electronic decay phenomena. However, the available Fano-ADC schemes are limited to the second-order treatment of the initial state and the first-order treatment of the final states of the decay. This confines the applicability of the Fano-ADC approach to first-order decay processes, e.g., normal but not double Auger decay (DAD), and compromises the numerical accuracy of the schemes through the unbalanced treatment of electronic correlation. Here, we introduce the ADC(2,2) approximation for singly ionized states, which describes both initial and final states of the decay up to second order. We use the new scheme to construct the Fano-ADC(2,2) approximation for the decay widths and show that it provides superior accuracy for the decay widths of a series of processes. Moreover, the Fano-ADC(2,2) method provides access to second-order decay processes, such as DAD, which are qualitatively beyond the reach of the previously available Fano-ADC implementations.} | ||||||
BibTeX:
@article{Kolorenc20,
author = {Kolorenč, P. and Averbukh, V.},
title = {{Fano-ADC(2,2) method for electronic decay rates}},
journal = {J. Chem. Phys.},
publisher = {AIP},
year = {2020},
volume = {152},
issue = {21},
pages = {214107},
numpages = {17},
note = {theory},
doi = {https://doi.org/10.1063/5.0007912}
}
|
||||||
| M. Khokhlova, L. Bahmanpour, N. Bachhawat, B. Cooper & V. Averbukh | Interatomic coulombic decay rate in endohedral complexes | 2020 | J. Phys. B: At. Mol. Opt. Phys. 53, 184002 |
|||
| Abstract: {Interatomic coulombic decay (ICD) in van der Waals endohedral complexes was predicted to be anomalously fast. However, the available theoretical calculations of the ICD rates in endohedral complexes only consider the equilibrium geometry, in which the encapsulated atom is located at the centre of the fullerene cage. Here we show analytically that the dominant contribution of the dipole plasmon resonance to ICD does not deviate from its equilibrium geometry value, while contributions of higher multipole plasmons to the ICD can be neglected for most atomic displacements possible for an endohedral complex at room temperature. This is in contrast to the behaviour predicted for ionic endohedral compounds. Our results show that the conclusion of the earlier works on the ultrafast character of the ICD in endohedral complexes holds generally for a wide range of geometries possible under a thermal distribution, rather than only for the equilibrium geometry.} | ||||||
BibTeX:
@article{Khokhlova20,
author = {Khokhlova, M. and Bahmanpour, L. and Bachhawat, N. and Cooper, B. and Averbukh, V.},
title = {{Interatomic coulombic decay rate in endohedral complexes}},
journal = {J. Phys. B: At. Mol. Opt. Phys.},
publisher = {IOP},
year = {2020},
volume = {53},
issue = {18},
pages = {184002},
numpages = {6},
note = {theory},
doi = {https://doi.org/10.1088/1361-6455/ab9f0c}
}
|
||||||
| G. Jabbari, K. Gokhberg & L.S. Cederbaum | Competition between interatomic Coulombic decay and autoionization of doubly-excited atoms | 2020 | Chem. Phys. Lett. 754, 137571 |
|||
| Abstract: {Doubly-excited atoms are known to autoionize. It is shown that in the presence of a neighboring atom, there is competition between autoionization and ICD (Interatomic Coulombic Decay) where the doubly-excited atom partially relaxes and the neighbor ionizes. Through a Rydberg series of doubly-excited states, the autoionization rate decreases in contrast to the ICD rate and ICD becomes dominant. Depending on the nature of the neighbor and the number of neighbors, other interatomic processes become operative even after autoionization, all demonstrating that the physics of doubly-excited species is strongly enriched in the presence of neighbors. Explicit examples are discussed.} | ||||||
BibTeX:
@article{Jabbari20,
author = {Jabbari, G. and Gokhberg, K. and Cederbaum, L. S.},
title = {{Competition between interatomic Coulombic decay and autoionization of doubly-excited atoms}},
journal = {Chem. Phys. Lett.},
publisher = {Elsevier},
year = {2020},
volume = {754},
pages = {137571},
numpages = {6},
note = {theory},
doi = {https://doi.org/10.1016/j.cplett.2020.137571}
}
|
||||||
| V. Guskov, F. Langkabel, M. Berg & A. Bande | An Impurity Effect for the Rates of the Interparticle Coulombic Decay | 2020 | QUARKS: Brazil. Electron. J. Phys. Chem. Mat. Sci. 3, 17 |
|||
| Abstract: {The interparticle Coulombic decay is a synchronized decay and ionization phenomenon occurring on two separated and only Coulomb interaction coupled electron binding sites. This publication explores how drastically small environmental changes in between the two sites, basically impurities, can alter the ionization properties and process rate, although the involved electronic transitions remain unaltered. A comparison among the present electron dynamics calculations for the example of different types of quantum dots, accommodating a one- or a two-dimensional continuum for the outgoing electron, and the well-investigated atomic and molecular cases with three-dimensional continuum, reveals that the impurity effect is most pronounced the stronger that electron is confined. This necessarily leads to challenges and opportunities in a quantum dot experiment to prove the interparticle Coulombic decay.} | ||||||
BibTeX:
@article{Guskov20,
author = {Guskov, V. and Langkabel, F. and Berg, M. and Bande, A.},
title = {{An Impurity Effect for the Rates of the Interparticle Coulombic Decay}},
journal = {QUARKS: Brazil. Electron. J. Phys. Chem. Mat. Sci.},
year = {2020},
volume = {3},
issue = {1},
pages = {17},
numpages = {14},
note = {theory},
doi = {https://doi.org/10.34019/2674-9688.2020.v3.31928}
}
|
||||||
| A. Grüll, A.B. Voitkiv & C. Müller | Influence of nuclear motion on resonant two-center photoionization | 2020 | Phys. Rev. A 102, 012818 |
|||
| Abstract: {The photoionization of an atom in the presence of a neighboring atom of a different species is studied. The latter first undergoes resonant photoexcitation, leading to an autoionizing state of the diatomic system. Afterwards, the excitation energy is transferred radiationlessly via a two-center Auger process to the other atom, causing its ionization. Assuming a fixed internuclear distance, it has been predicted theoretically that this indirect ionization pathway can strongly dominate over the direct photoionization. Here, we extend the theory of resonant two-center photoionization by including the nuclear motion in van der Waals molecules. An analytical formula is derived reflecting the influence of molecular vibrational dynamics on the relative strength of the two-center channel. For the specific example of Li-He dimers, we show that the two-center autoionizing resonances are split by the nuclear motion into multiplets, with the resonance lines reaching a comparable level of enhancement over direct photoionization as is obtained in a model based on spatially fixed nuclei.} | ||||||
BibTeX:
@article{Gruell20a,
author = {Grüll, A. and Voitkiv, A. B. and Müller, C.},
title = {{Influence of nuclear motion on resonant two-center photoionization}},
journal = {Phys. Rev. A},
publisher = {American Physical Society},
year = {2020},
volume = {102},
issue = {1},
pages = {012818},
numpages = {10},
note = {theory},
doi = {https://doi.org/10.1103/PhysRevA.102.012818}
}
|
||||||
| A. Grüll, A.B. Voitkiv & C. Müller | Interatomic-distance dependence of resonant energy-transfer phenomena | 2020 | Phys. Rev. Res. 2, 033303 |
|||
| Abstract: {It is well known that interatomic or intermolecular interactions driven by two-center electronic dipole-dipole correlations fall off rapidly with the intersite distance. We show, however, that the effective strength of interatomic reaction channels, which are triggered by a resonant field, can exhibit a nonmonotonous distance dependence, being strongly reduced when the atoms come closer. This surprising result is demonstrated by considering resonant two-center photoionization as an example. Our findings are supported by available experimental data.} | ||||||
BibTeX:
@article{Gruell20b,
author = {Grüll, A. and Voitkiv, A. B. and Müller, C.},
title = {{Interatomic-distance dependence of resonant energy-transfer phenomena}},
journal = {Phys. Rev. Res.},
publisher = {American Physical Society},
year = {2020},
volume = {2},
issue = {3},
pages = {033303},
numpages = {5},
note = {theory},
doi = {https://doi.org/10.1103/PhysRevResearch.2.033303}
}
|
||||||
| J.D. Gorfinkiel | Electron collisions with molecules and molecular clusters | 2020 | Eur. Phys. J. D 74, 51 |
|||
| Abstract: {State-of-the art computational studies of electron collisions with molecules and small molecular clusters are illustrated with results obtained from the application of the R-matrix method and the UKRMol/UKRMol+ suites. High-level calculations of electronic excitation cross sections and core-excited resonances, mainly of core-excited shape character, show excellent agreement with experiment for mid-size molecules like pyrimidine and thiophene. Simpler calculations are paving the way for an in-depth understanding of the effect of hydration on resonance formation: how the shift in resonance energy depends on the characteristics of the hydrogen bond and the resonance being studied. Finally, applications of the software to a little studied process, interatomic coulombic electron capture are also illustrated.} | ||||||
BibTeX:
@article{Gorfinkiel20,
author = {Gorfinkiel, J. D.},
title = {{Electron collisions with molecules and molecular clusters}},
journal = {Eur. Phys. J. D},
publisher = {Springer},
year = {2020},
volume = {74},
issue = {3},
pages = {51},
numpages = {6},
note = {theory},
doi = {https://doi.org/10.1140/epjd/e2020-100550-7}
}
|
||||||
| E. Fasshauer & L.B. Madsen | Time-resolved spectroscopy of interparticle Coulombic decay processes | 2020 | Phys. Rev. A 101, 043414 |
|||
| Abstract: {We report the theory for time-resolved spectator resonant interparticle Coulombic decay (ICD) processes. Following excitation by a short extreme ultraviolet pulse, the spectrum of the resonant ICD electron develops. Strong-field ionization is imagined to quench the decay at different time delays and to initiate regular ICD. In this latter process, the ICD electron signal can be measured without interference effects. The typical lifetimes of ICD processes allow for the observation of oscillations of the time- and energy-differential ionization probability. We propose to utilize this oscillation to measure lifetimes of electronic decay processes.} | ||||||
BibTeX:
@article{Fasshauer20,
author = {Fasshauer, E. and Madsen, L. B.},
title = {{Time-resolved spectroscopy of interparticle Coulombic decay processes}},
journal = {Phys. Rev. A},
publisher = {American Physical Society},
year = {2020},
volume = {101},
issue = {4},
pages = {043414},
numpages = {11},
note = {theory},
doi = {https://doi.org/10.1103/PhysRevA.101.043414}
}
|
||||||
| A. Eckey, A.B. Voitkiv & C. Müller | Resonant single-photon double ionization driven by combined intra- and interatomic electron correlations | 2020 | J. Phys. B: At. Mol. Opt. Phys. 53, 055001 |
|||
| Abstract: {The double ionization of an atom by single-photon absorption in the presence of a neighbouring atom is studied. The latter is, first, resonantly photoexcited and, afterwards, transfers the excitation energy radiationlessly to the other atom, leading to its double ionization. The process relies on the combined effect of interatomic and intra-atomic electron correlations. It can dominate over the direct double photoionization by several orders of magnitude at interatomic distances up to a few nanometers. The relative position of the neighbouring atom is shown to exert a characteristic influence on the angular distribution of emitted electrons.} | ||||||
BibTeX:
@article{Eckey20,
author = {Eckey, A. and Voitkiv, A. B. and Müller, C.},
title = {{Resonant single-photon double ionization driven by combined intra- and interatomic electron correlations}},
journal = {J. Phys. B: At. Mol. Opt. Phys.},
publisher = {IOP},
year = {2020},
volume = {53},
issue = {5},
pages = {055001},
numpages = {8},
note = {theory},
doi = {https://doi.org/10.1088/1361-6455/ab5d91}
}
|
||||||
| L.S. Cederbaum | Fragmentation of Molecules by Virtual Photons from Remote Neighbors | 2020 | J. Phys. Chem. Lett. 11, 8964 |
|||
| Abstract: {It is shown that a molecule can dissociate by the energy transferred from a remote neighbor. This neighbor can be an excited neutral or ionic atom or molecule. If it is an atom, then the transferred energy is, of course, electronic, and in the case of molecules, it can also be vibrational. Explicit examples are given which demonstrate that the transfer can be highly efficient at distances where there is no bonding between the transmitter and the dissociating molecule.} | ||||||
BibTeX:
@article{Cederbaum20,
author = {Cederbaum, L. S.},
title = {{Fragmentation of Molecules by Virtual Photons from Remote Neighbors}},
journal = {J. Phys. Chem. Lett.},
publisher = {American Chemical Society},
year = {2020},
volume = {11},
issue = {21},
pages = {8964},
numpages = {6},
note = {theory},
doi = {https://doi.org/10.1021/acs.jpclett.0c02259}
}
|
||||||
| R. Cabrera-Trujillo, O. Vendrell & L.S. Cederbaum | Interatomic Coulombic decay of a Li dimer in a coupled electron and nuclear dynamics approach | 2020 | Phys. Rev. A 102, 032820 |
|||
| Abstract: {Interatomic Coulombic decay (ICD) is a fundamental process between atoms or molecules via a neighbor interaction that produces a relaxation of an electronically excited atom or molecule when embedded in an environment. Due to the physical nature of the process, the electronic and nuclear degrees of freedom are coupled. In this paper, we study the ICD process for a lithium dimer by means of the electron and nuclear dynamics (END) approach. The END approach incorporates a full time-dependent description of the electronic and nuclear degrees of freedom, although its current version does not properly account for continuum states and has limitations in the electronic description by using a single determinantal wave function. Despite this, we confirm that the ICD process takes place via a dipole interaction that induces the nuclear motion of the dimer with a consequent electronic population transfer to higher excited states simulating the ionization process. When the dimer approaches a distance of around 11.5 a.u. (6 Å), this ionization process takes place due to the dipole coupling and occurs at the place of the strongest attractive dipole force. Passing that point, we find that the two lithium atoms repel each other via a Coulomb explosion process followed with a consequent kinetic-energy release (KER). We determine the KER and the timing of the ICD process. We point out the strengths and weaknesses of the END approach and the required enhancements to account for a better description of the ICD process in a coupled electron and nuclear dynamics.} | ||||||
BibTeX:
@article{Cabrera-Trujillo20,
author = {Cabrera-Trujillo, R. and Vendrell, O. and Cederbaum, L. S.},
title = {{Interatomic Coulombic decay of a Li dimer in a coupled electron and nuclear dynamics approach}},
journal = {Phys. Rev. A},
publisher = {American Physical Society},
year = {2020},
volume = {102},
issue = {3},
pages = {032820},
numpages = {7},
note = {theory},
doi = {https://doi.org/10.1103/PhysRevA.102.032820}
}
|
||||||
| A. Ben-Asher, A. Landau, L.S. Cederbaum & N. Moiseyev | Quantum Effects Dominating the Interatomic Coulombic Decay of an Extreme System | 2020 | J. Phys. Chem. Lett. 11, 6600 |
|||
| Abstract: {LiHe is an extreme open-shell system. It is among the weakest bound systems known, and its mean interatomic distance extends dramatically into the classical forbidden region. Upon 1s → 2p excitation of He, interatomic Coulombic decay (ICD) takes place in which the electronically excited helium atom relaxes and transfers its excess energy to ionize the neighboring lithium atom. A substantial part of the decay is found to be to the dissociation continuum producing Li+ and He atoms. The distribution of the kinetic energy released by the ICD products is found to be highly oscillatory. Its analysis reveals that quantum phase shifts between the decaying states and the dissociating final states are controlling this ICD reaction. The semiclassical reflection principle, which commonly explains ICD reactions, fails. The process is expected to be amenable to experiment.} | ||||||
BibTeX:
@article{BenAsher20,
author = {Ben-Asher, A. and Landau, A. and Cederbaum, L. S. and Moiseyev, N.},
title = {{Quantum Effects Dominating the Interatomic Coulombic Decay of an Extreme System}},
journal = {J. Phys. Chem. Lett.},
publisher = {American Chemical Society},
year = {2020},
volume = {11},
issue = {16},
pages = {6600},
numpages = {6},
note = {theory},
doi = {https://doi.org/10.1021/acs.jpclett.0c01974}
}
|
||||||
| H. Agueny, M. Pesche, B. Lutet-Toti, T. Miteva, A. Molle, J. Caillat & N. Sisourat | Interparticle coulombic decay in coupled quantum dots: Enhanced energy transfer via bridge assisted mechanisms | 2020 | Phys. Rev. B 101, 195431 |
|||
| Abstract: {Interparticle coulombic decay (ICD) is an efficient energy transfer process between two weakly interacting systems. ICD was recently proposed as the underlying fundamental mechanism for technological purposes based on quantum dot nanostructures, such as wavelength-sensitive detectors. Via ICD, an excited donor quantum dot releases its excess energy by ionizing a neighboring acceptor dot. Here, we demonstrate that the presence of a third (ICD inactive) quantum dot can serve as a bridge between the two dots, which is shown to result in an enhancement of the efficiency of the ICD-mediated energy transfer. Furthermore, our results show that this enhancement is found to be robust against change in the characteristics of the bridge quantum dot, particularly the depth and size. On the other hand, its relative position with respect to the donor and acceptor dots is found to foster ICD when it is located in between the two dots. Our findings provide new insights for the development of ICD-based nanostructure technologies, particularly for rational design of three coupled quantum dots.} | ||||||
BibTeX:
@article{Agueny20,
author = {Agueny, H. and Pesche, M. and Lutet-Toti, B. and Miteva, T. and Molle, A. and Caillat, J. and Sisourat, N.},
title = {{Interparticle coulombic decay in coupled quantum dots: Enhanced energy transfer via bridge assisted mechanisms}},
journal = {Phys. Rev. B},
publisher = {American Physical Society},
year = {2020},
volume = {101},
issue = {19},
pages = {195431},
numpages = {6},
note = {theory},
doi = {https://doi.org/10.1103/PhysRevB.101.195431}
}
|
||||||
| A. Molle, A. Dubois, J.D. Gorfinkiel, L.S. Cederbaum & N. Sisourat | Fano interferences in environment-enabled electron capture | 2021 | Phys. Rev. A 103, 012808 |
|||
| Abstract: {Interatomic Coulombic electron capture (ICEC) is an environment-assisted process in which a free electron can efficiently attach to a quantum system by transferring the excess energy of the electron capture to a neighbor ionizing it. Using the ab initio R-matrix method, we show that Fano profiles, resulting from interferences between the ICEC final states and resonant states, appear in the ICEC cross sections even at extremely large system-neighbor separations. We identify several types of resonant states depending on their decay pathways which may involve long-range electron and energy transfer. ICEC is a fundamental process and the interferences lead to substantial enhancement or decrease of the cross sections. The present investigation is therefore of general relevance in many contexts wherever electron capture in an environment takes place.} | ||||||
BibTeX:
@article{Molle21a,
author = {Molle, A. and Dubois, A. and Gorfinkiel, J. D. and Cederbaum, L. S. and Sisourat, N.},
title = {{Fano interferences in environment-enabled electron capture}},
journal = {Phys. Rev. A},
publisher = {American Physical Society},
year = {2021},
volume = {103},
issue = {1},
pages = {012808},
numpages = {5},
note = {theory},
doi = {https://doi.org/10.1103/PhysRevA.103.012808}
}
|
||||||
| A. Molle, A. Dubois, J.D. Gorfinkiel, L.S. Cederbaum & N. Sisourat | Electron attachment to a proton in water by interatomic Coulombic electron capture: An R-matrix study | 2021 | Phys. Rev. A 104, 022818 |
|||
| Abstract: {Interatomic Coulombic electron capture (ICEC) is an environment-enabled electron capture process in which a free electron can efficiently attach to a quantum system by transferring the excess energy to a neighbor thus ionizing it. Using the ab initio R-matrix method, we investigate the electron attachment to a proton in the neighborhood of a water molecule. The corresponding ICEC cross sections exhibit clear Fano profiles, resulting from interferences between the ICEC final states and resonant states. These Fano interferences, observed in the total ICEC cross sections, were discussed in our recent work on large system-neighbor separations [A. Molle et al., Phys. Rev. A 103, 012808 (2021)]. In the present study, we report on the ICEC cross sections at shorter distances which are relevant in biological and biochemical contexts. Furthermore, we investigate the partial ICEC cross sections and demonstrate that the ionization of a water molecule via ICEC is substantially different from that due to direct photoionization. Finally, we show that the distortion of the equilibrium geometry of the water molecule due to the presence of the proton influences the ICEC process.} | ||||||
BibTeX:
@article{Molle21b,
author = {Molle, A. and Dubois, A. and Gorfinkiel, J. D. and Cederbaum, L. S. and Sisourat, N.},
title = {{Electron attachment to a proton in water by interatomic Coulombic electron capture: An R-matrix study}},
journal = {Phys. Rev. A},
publisher = {American Physical Society},
year = {2021},
volume = {104},
issue = {2},
pages = {022818},
numpages = {5},
note = {theory},
doi = {https://doi.org/10.1103/PhysRevA.104.022818}
}
|
||||||
| F. Langkabel & A. Bande | Three-electron dynamics of the interparticle Coulombic decay with two-dimensional continuum confinement | 2021 | J. Chem. Phys. 154, 054111 |
|||
| Abstract: {In a pair of self-assembled or gated laterally arranged quantum dots, an electronically excited state can undergo interparticle Coulombic decay. Then, an electron from a neighbor quantum dot is emitted into the electronic continuum along the two available dimensions. This study proves that the process is not only operative among two but also among three quantum dots, where a second electron-emitting dot causes a rate increase by a factor of two according to the predictions from the analytical Wigner-Weisskopf rate equation. The predictions hold over the complete range of conformation angles among the quantum dots and over a large range of distances. Electron dynamics was calculated by multiconfiguration time-dependent Hartree and is, irrespective of the large number of discrete variable representation grid points, feasible after having developed an OpenACC graphic card compilation of the program.} | ||||||
BibTeX:
@article{Langkabel21,
author = {Langkabel, F. and Bande, A.},
title = {{Three-electron dynamics of the interparticle Coulombic decay with two-dimensional continuum confinement}},
journal = {J. Chem. Phys.},
publisher = {AIP},
year = {2021},
volume = {154},
issue = {5},
pages = {054111},
numpages = {9},
note = {theory},
doi = {https://doi.org/10.1063/5.0037806}
}
|
||||||
| T. Kirchner | Indication of strong interatomic Coulombic decay in slow He2+–Ne2 collisions | 2021 | J. Phys. B: At. Mol. Opt. Phys. 54, 205201 |
|||
| Abstract: {Electron removal in collisions of alpha particles with neon dimers is studied using an independent-atom-independent-electron model based on the semiclassical approximation of heavy-particle collision physics. The dimer is assumed to be frozen at its equilibrium bond length and collision events for the two ion–atom subsystems are combined in an impact parameter by impact parameter fashion for three mutually perpendicular orientations. Both frozen atomic target and dynamic response model calculations are carried out using the coupled-channel two-center basis generator method. We pay particular attention to inner-valence Ne(2s) electron removal, which is associated with interatomic Coulombic decay (ICD), resulting in low-energy electron emission and dimer fragmentation. Our calculations confirm a previous experimental result at 150 keV/amu impact energy regarding the relative strength of ICD compared to direct electron emission. They further indicate that ICD is the dominant Ne+ + Ne+ fragmentation process below 10 keV/amu, suggesting that a strong low-energy electron yield will be observed in the ion–dimer system in a regime in which the creation of continuum electrons is a rare event in the ion–atom problem.} | ||||||
BibTeX:
@article{Kirchner21,
author = {T. Kirchner},
title = {{Indication of strong interatomic Coulombic decay in slow He2+–Ne2 collisions}},
journal = {J. Phys. B: At. Mol. Opt. Phys.},
publisher = {IOP Publishing},
year = {2021},
volume = {54},
pages = {205201},
note = {theory},
doi = {https://doi.org/10.1088/1361-6455/ac34e0}
}
|
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| A. Jacob, C. Müller & A.B. Voitkiv | Single ionization of an asymmetric diatomic system by relativistic charged projectiles | 2021 | Phys. Rev. A 103, 042804 |
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| Abstract: {We study single ionization of a heteroatomic system by charged projectiles whose velocity v approaches the speed of light c. The system is formed by two loosely bound atomic species, A and B, with the ionization potential of A being smaller than excitation energy for a dipole-allowed transition in B. In such a case, three single ionization channels occur: (i) single-center ionization of atom A, (ii) single-center ionization of atom B, and (iii) two-center ionization of B. While (i) and (ii) are the well known mechanism of direct impact ionization of a single atom, in channel (iii) ionization of A proceeds via impact excitation of B with consequent radiationless transfer of excitation energy—via (long-range) two-center electron-electron correlations—to A, leading to its ionization. We show that, close to the resonance energy, the two-center channel (iii) is so enormously strong that its contribution remains dominant even if the range of emission energies ∼1 eV, which is orders of magnitude broader than its width, is considered. The influence of relativistic effects, caused by a high collision velocity, on the angular distribution of emitted electrons may be quite strong even at γ=1/√(1−v2/c2) ≈ 2. However, in the energy distribution and the total cross section, these effects become substantial only at γ≫1. Relativistic effects arising due to a large size of the two-atomic system are shown to be very weak even for a 7Li–He dimer whose mean size is about 28 Å.} | ||||||
BibTeX:
@article{Jacob21,
author = {Jacob, A. and Müller, C. and Voitkiv, A. B.},
title = {{Single ionization of an asymmetric diatomic system by relativistic charged projectiles}},
journal = {Phys. Rev. A},
publisher = {American Physical Society},
year = {2021},
volume = {103},
issue = {4},
pages = {042804},
numpages = {15},
note = {theory},
doi = {https://doi.org/10.1103/PhysRevA.103.042804}
}
|
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| K. Gokhberg, A.I. Kuleff & L.S. Cederbaum | Electronic Decay Cascades in Chemical Environment | 2021 | Molecular Spectroscopy and Quantum Dynamics , 163 |
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| Abstract: {Core-excited and core-ionized states created by absorption of X-ray photons carry an enormous energy of hundreds to thousands electronvolts. In the gas phase this energy is dissipated primarily in the Auger decay process or Auger decay cascades, whereby one or several electrons are emitted into the continuum producing multiply charged ions. Two interatomic electronic decay processes, interatomic Coulombic decay (ICD) and electron-transfer mediated decay (ETMD), ensure the efficient dissipation of energy beyond the Auger decay should X-ray absorption take place in a chemical medium characterized by weak van der Waals or hydrogen bonds. Numerous experiments and theoretical results have demonstrated that the Auger–interatomic decay cascades represent a common de-excitation mechanism of core vacancies in medium, whose length and complexity increase with increasing photon energy. Such cascades offer a means for very fast dissipation of the energy which is deposited by the photon into the system. They are also responsible for massive radiation damage to the molecules around the photoabsorption site. Surprisingly, ICD cascades remain a potent mechanism of energy dissipation also when the energy is invested in a cluster by a laser not as a single high energy photon but as multiple low energy ones. The recent research of the electronic decay in chemical media presented in this chapter strives to clarify the physical and chemical consequences of weakly subjecting bound clusters to the highly energetic light provided by modern light sources.} | ||||||
BibTeX:
@inbook{Gokhberg21,
author = {Gokhberg, K. and Kuleff, A. I. and Cederbaum, L. S.},
title = {{Electronic Decay Cascades in Chemical Environment}},
journal = {Molecular Spectroscopy and Quantum Dynamics},
publisher = {Elsevier},
year = {2021},
pages = {163},
numpages = {35},
note = {theory},
doi = {https://doi.org/10.1016/B978-0-12-817234-6.00010-6}
}
|
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| A. Ghosh, S. Pal & N. Vaval | Interatomic Coulombic decay in Neon-Helium cluster: a complex absorbing potential based equation-of-motion coupled cluster investigation | 2021 | Mol. Phys. 119, 1884300 |
|||
| Abstract: {The interatomic Coulombic decay (ICD) of the Ne(2s-1) and Ne(2s-12p-1) states in neon-helium dimer is studied using highly accurate complex absorbing potential based equation-of-motion coupled cluster (CAP-EOMCC) method. The ICD decay process for the Ne(2s-1) state in neon-helium dimer is closed at its equilibrium bond distance. However, the decay channel is open at large bond distance of 6.2 Å. The decay channel for the double ionised Ne(2s-12p-1) state is open at 3.46 Å. From our calculations, we have noticed that the decay rate of Ne(2s-12p-1) state in neon-helium dimer is four times faster compared to the Ne(2s-1) state. We have also investigated how the decay rate of Ne(2s-1) state in neon-helium cluster varies in the presence of different helium environment.} | ||||||
BibTeX:
@article{Ghosh21a,
author = {Ghosh, A. and Pal, S. and Vaval, N.},
title = {{Interatomic Coulombic decay in Neon-Helium cluster: a complex absorbing potential based equation-of-motion coupled cluster investigation}},
journal = {Mol. Phys.},
publisher = {Taylor & Francis},
year = {2021},
volume = {119},
issue = {9},
pages = {1884300},
numpages = {9},
note = {theory},
doi = {https://doi.org/10.1080/00268976.2021.1884300}
}
|
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| A. Ghosh, L.S. Cederbaum & K. Gokhberg | Signature of the neighbor's quantum nuclear dynamics in the electron transfer mediated decay spectra | 2021 | Chem. Sci. 12, 9379 |
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| Abstract: {We computed fully quantum nuclear dynamics, which accompanies electron transfer mediated decay (ETMD) in weakly bound polyatomic clusters. We considered two HeLi2 clusters - with Li2 being either in the singlet electronic ground state or in the triplet first excited state - in which ETMD takes place after ionization of He. The electron transfer from Li22 to He+ leads to the emission of another electron from Li2 into the continuum. Due to the weak binding of He to Li2 in the initial states of both clusters, the involved nuclear wavepackets are very extended. This makes both the calculation of their evolution and the interpretation of the results difficult. We showed that despite the highly delocalized nature of the wavepackets the nuclear dynamics in the decaying state is imprinted on the ETMD electron spectra. The analysis of the latter helps understanding the effect which electronic structure and binding strength in the cluster produce on the quantum motion of the nuclei in the decaying state. The results produce a detailed picture of this important charge transfer process in polyatomic systems.} | ||||||
BibTeX:
@article{Ghosh21b,
author = {Ghosh, A. and Cederbaum, L. S. and Gokhberg, K.},
title = {{Signature of the neighbor's quantum nuclear dynamics in the electron transfer mediated decay spectra}},
journal = {Chem. Sci.},
publisher = {RSC},
year = {2021},
volume = {12},
issue = {27},
pages = {9379},
numpages = {7},
note = {theory},
doi = {https://doi.org/10.1039/D1SC01478A}
}
|
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| J. Fedyk, K. Gokhberg & L.S. Cederbaum | Theory of double ionization of a neighboring molecule by interatomic Coulombic decay | 2021 | Phys. Rev. A 103, 022816 |
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| Abstract: {Several known processes, such as single-photon double ionization and double Auger decay, result in correlated emission of two electrons from an atom or molecule. The ratio of double to single ionization in these processes usually amounts only to several percent. Recently, an experiment was reported in helium droplets doped with alkali dimers, where double ionization of the dimer after excitation of the helium proceeds via interatomic Coulombic decay and occurs with an efficiency comparable to that of single ionization via the usual interatomic Coulombic decay. Motivated by these experimental results, we investigate here the theory of this double interatomic Coulombic decay (dICD) process. First, we develop an explicit asymptotic formula for the decay width of dICD based on the assumption that the electronically excited system providing the necessary excess energy and its neighbor are spatially well separated. This formula contains only quantities accessible experimentally for the separated entities - the system and its neighbor. Second, we derive a general analytical expression for the decay width of dICD by using many-body perturbation theory. Finally, we investigated the efficiency of dICD for experimentally realizable small atomic and molecular clusters employing the asymptotic formula.} | ||||||
BibTeX:
@article{Fedyk21,
author = {Fedyk, J. and Gokhberg, K. and Cederbaum, L. S.},
title = {{Theory of double ionization of a neighboring molecule by interatomic Coulombic decay}},
journal = {Phys. Rev. A},
publisher = {American Physical Society},
year = {2021},
volume = {103},
issue = {2},
pages = {022816},
numpages = {17},
note = {theory},
doi = {https://doi.org/10.1103/PhysRevA.103.022816}
}
|
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| P.C. Deshmukh, J. Jose, H.R. Varma & S.T. Manson | Electronic structure and dynamics of confined atoms | 2021 | Eur. Phys. J. D 75, 166 |
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| Abstract: {Confined atomic systems are of great importance owing a multitude of possible applications in various areas of science and technology. Of particular interest are atoms encaged in the C60 molecule, A@C60, since the near-spherical symmetry of C60 simplifies theoretical studies, and the stability of C60 renders it amenable to experimental examination. A review of investigations of the electronic structure and dynamics of A@C60 is presented in this manuscript focusing on developments in the last decade. Addressed mainly are how the confinement affects electronic structure properties such as ionization potentials, localization of atomic electrons, Shannon entropy, correlation effects, relativistic interactions, and others. In the area of dynamics, photoionization and e-A@C60 scattering are reviewed and summarized, and the major effects of confinement on the dynamical properties, e.g., confinement resonances, hybridization, Wigner time delay, are delineated.} | ||||||
BibTeX:
@article{Deshmukh21,
author = {Deshmukh, P. C. and Jose, J. and Varma, H. R. and Manson, S. T.},
title = {{Electronic structure and dynamics of confined atoms}},
journal = {Eur. Phys. J. D},
publisher = {Springer},
year = {2021},
volume = {75},
issue = {6},
pages = {166},
numpages = {32},
note = {theory},
doi = {https://doi.org/10.1140/epjd/s10053-021-00151-2}
}
|
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| R. De, E. Ali, S.T. Manson & H.S. Chakraborty | Density functional study of the variants of inter-Coulombic decay resonances in the photoionization of Cl@C60 | 2021 | Phys. Scr. 96, 104007 |
|||
| Abstract: {Inter-Coulombic decay (ICD) resonances in the photoionization of Cl@C60 endofullerene molecule are calculated using a perturbative density functional theory (DFT) method. This is the first ICD study of an open shell atom in a fullerene cage. Three classes of resonances are probed: (i) Cl inner vacancies decaying through C60 outer continua, (ii) C60 inner vacancies decaying through Cl outer continua, and (iii) inner vacancies of either system decaying through the continua of Cl-C60 hybrid levels, the hybrid Auger-ICD resonances. Comparisons with Ar@C60 results reveal that the properties of hybrid Auger-ICD resonances are affected by the extent of level hybridization.} | ||||||
BibTeX:
@article{De21,
author = {De, R. and Ali, E. and Manson, S. T. and Chakraborty, H. S.},
title = {{Density functional study of the variants of inter-Coulombic decay resonances in the photoionization of Cl@C60}},
journal = {Phys. Scr.},
publisher = {IOP},
year = {2021},
volume = {96},
issue = {10},
pages = {104007},
numpages = {9},
note = {theory},
doi = {https://doi.org/10.1088/1402-4896/ac0e06}
}
|
||||||
| L.S. Cederbaum & A.I. Kuleff | Impact of cavity on interatomic Coulombic decay | 2021 | Nat. Commun. 12, 4083 |
|||
| Abstract: {The interatomic Coulombic decay (ICD) is an efficient electronic decay process of systems embedded in environment. In ICD, the excess energy of an excited atom A is efficiently utilized to ionize a neighboring atom B. In quantum light, an ensemble of atoms A form polaritonic states which can undergo ICD with B. Here we investigate the impact of quantum light on ICD and show that this process is strongly altered compared to classical ICD. The ICD rate depends sensitively on the atomic distribution and orientation of the ensemble. It is stressed that in contrast to superposition states formed by a laser, forming polaritons by a cavity enables to control the emergence and suppression, as well as the efficiency of ICD.} | ||||||
BibTeX:
@article{Cederbaum21,
author = {Cederbaum, L. S. and Kuleff, A. I.},
title = {{Impact of cavity on interatomic Coulombic decay}},
journal = {Nat. Commun.},
publisher = {Nature Research},
year = {2021},
volume = {12},
pages = {4083},
numpages = {8},
note = {theory},
doi = {https://doi.org/10.1038/s41467-021-24221-6}
}
|
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| R. Kumar, A. Ghosh & N. Vaval | Decay Processes in Cationic Alkali Metals in Microsolvated Clusters: A Complex Absorbing Potential Based Equation-of-Motion Coupled Cluster Investigation | 2022 | J. Chem. Theory Comput. 18, 807-816 |
|||
| Abstract: {We have employed the highly accurate complex absorbing potential based ionization potential equation-of-motion coupled cluster singles and doubles (CAP-IP-EOM-CCSD) method to study the various intermolecular decay processes in ionized metals (Li+, Na+, K+) microsolvated by water molecules. For the Li atom, the electron is ionized from the 1s subshell. However, for Na and K atoms, the electron is ionized from 2s and both 2s and 2p subshells, respectively. We have investigated decay processes for the Li+–(H2O)n (n = 1–3) systems, as well as Na+–(H2O)n (n = 1, 2), and K+–H2O. The lithium cation in water can decay only via electron transfer mediated decay (ETMD) as there are no valence electrons in lithium. We have investigated how the various decay processes change in the presence of different alkali metal atoms and how the increasing number of water molecules play a significant role in the decay of microsolvated systems. To see the effect of the environment, we have studied Li+–NH3 in comparison to Li+–H2O. In the case of Na+–H2O, we have studied the impact of bond distance on the decay width. The effect of polarization on decay width was checked for the X+–H2O (X = Li, Na) systems. We used the PCM model to study the polarization effect. We have compared our results with existing theoretical and experimental results wherever available in the literature.} | ||||||
BibTeX:
@article{Kumar22,
author = {Kumar, R. and Ghosh, A. and Vaval, N.},
title = {{Decay Processes in Cationic Alkali Metals in Microsolvated Clusters: A Complex Absorbing Potential Based Equation-of-Motion Coupled Cluster Investigation}},
journal = {J. Chem. Theory Comput.},
year = {2022},
volume = {18},
pages = {807-816},
note = {theory},
doi = {https://doi.org/10.1021/acs.jctc.1c01036}
}
|
||||||
| C. Hoffmeister, C. Müller & A.B. Voitkiv | Resonant interatomic Coulombic decay in a laser field | 2022 | Phys. Rev. A 105, 042803 |
|||
| Abstract: {We consider photoionization in a system of two atoms of different species caused by a laser field. In this process an inner-valence vacancy, created by photoexcitation in one of the atoms, decays not only due to intra- but also interatomic electron-electron correlations with the energy release in the latter case being transferred to the other atom which is ionized. We show that when the intensity of the laser field increases this photoionization process--due to Rabi oscillations and Pauli blocking--may acquire qualitatively new features in its time evolution and the electron emission spectra.} | ||||||
BibTeX:
@article{Hoffmeister22,
author = {Hoffmeister, C. and Müller, C. and Voitkiv, A. B.},
title = {{Resonant interatomic Coulombic decay in a laser field}},
journal = {Phys. Rev. A},
year = {2022},
volume = {105},
issue = {4},
pages = {042803},
numpages = {8},
note = {theory},
doi = {https://doi.org/10.1103/PhysRevA.105.042803}
}
|
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| F. Grüll, A.B. Voitkiv & C. Müller | Relevance of dissociative molecular states for resonant two-center photoionization of heteroatomic dimers | 2022 | J. Phys. B: At. Mol. Opt. Phys. 55, 245101 |
|||
| Abstract: {Photoionization of a weakly bound van-der-Waals dimer, composed of two atomic species A and B, is studied theoretically. Atom A can be ionized either directly or via an indirect two-center channel, where atom B is first resonantly photoexcited and, afterwards, transfers the excitation energy via long-range electron–electron correlations radiationlessly to atom A, causing its ionization. By taking the vibrational nuclear motion of the dimer during the process into account, we analyze the contributions to the photoionization cross section from bound and dissociative molecular states in the final A+–B system. For the specific example of a LiHe dimer we show (a) that substantial contributions to both ionization mechanisms result from dissociative Li+ + He states and (b) that the two-center pathway strongly dominates over the direct photoionization channel for photon energies close to one of the molecular LiHe resonances.} | ||||||
BibTeX:
@article{Gruell22,
author = {Grüll, F. and Voitkiv, A. B. and Müller, C.},
title = {{Relevance of dissociative molecular states for resonant two-center photoionization of heteroatomic dimers}},
journal = {J. Phys. B: At. Mol. Opt. Phys.},
publisher = {IOP Publishing},
year = {2022},
volume = {55},
pages = {245101},
note = {theory},
doi = {https://doi.org/10.1088/1361-6455/aca0d3}
}
|
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| J. Franz & S.Y. Buhmann | Purcell modification of Auger and interatomic Coulombic decay | 2022 | New J. Phys. 24, 043002 |
|||
| Abstract: {An excited two-atom system can decay via different competing relaxation processes. If the excess energy is sufficiently high the system may not only relax via spontaneous emission but can also undergo interatomic Coulombic decay or even Auger decay. We provide analytical expressions for the rates by including them into the same quantum optical framework on the basis of macroscopic quantum electrodynamics. By comparing the rates in free space we derive the atomic properties determining which decay channel dominates the relaxation. We show that by modifying the excitation propagation of the respective process via macroscopic bodies, in the spirit of the Purcell effect, one can control the ratio between the two dominating decay rates. We can relate the magnitude of the effect to characteristic length scales of each process, analyse the impact of a simple close-by surface onto a general two-atom system in detail and discuss the effect of a cavity onto the decay rates. We finally apply our theory to the example of a doubly excited HeNe-dimer.} | ||||||
BibTeX:
@article{Franz22,
author = {Franz, J. and Buhmann, S. Y.},
title = {{Purcell modification of Auger and interatomic Coulombic decay}},
journal = {New J. Phys.},
publisher = {IOP Publishing},
year = {2022},
volume = {24},
pages = {043002},
note = {theory},
doi = {https://doi.org/10.1088/1367-2630/ac5caa}
}
|
||||||
| S. Chatterjee | Impact of intense ultrashort laser on Interatomic Coulombic decay in the NeAr dimer | 2022 | J. Electron Spectr. Relat. Phenom. 260, 147253 |
|||
| Abstract: {The exposure of Ne-Ar dimer to an intense ultrashort laser can trigger a variety of competing ionization processes in addition to the already predicted interatomic Coulombic decay (ICD). The question of how and to what extent these competing ionization processes influence the line shape of the electron spectrum obtained for an ICD is addressed to in this work. The calculations predict that ionization from the ICD and final ionic states significantly influences the line shape of the electron spectrum. The time resolved electron spectrum for an only ICD process was calculated by employing an analytical expression. A line splitting in the ICD spectrum is observed at a comparatively higher peak intensity and systematic analysis involving time resolved electron spectrum indicates that the splitting is caused due to the effect of photoionization from the final ionic state. The effects of the ponderomotive shift of the free electron released prior to the ICD step on the ICD electron spectra were also estimated.} | ||||||
BibTeX:
@article{Chatterjee22,
author = {Chatterjee, S.},
title = {{Impact of intense ultrashort laser on Interatomic Coulombic decay in the NeAr dimer}},
journal = {J. Electron Spectr. Relat. Phenom.},
year = {2022},
volume = {260},
pages = {147253},
note = {theory},
doi = {https://doi.org/10.1016/j.elspec.2022.147253}
}
|
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| R. Cabrera-Trujillo, O. Vendrell & L.S. Cederbaum | Dipole-induced processes in HeH+ produced by an excited Li(2p) neighbor: From charge transfer to virtual photon dissociation, and formation of LiH and LiHe | 2022 | Phys. Rev. A 105, 053104 |
|||
| Abstract: {Dipole interaction between neighbor systems is of importance in the behavior of atoms and molecules as it produces distortion in the electronic structure of the system. In this work, we study the dipole processes in a HeH+ molecule induced by an initially excited lithium atom placed at an R0 distance from the center of mass of the molecule. The electronic and nuclear degrees of freedom are treated by the electron-nuclear dynamics approach as it allows a time-dependent description of the electronic and nuclear dynamics. The energy transferred from the neighbor excited lithium atom to the HeH+ molecule is distributed into several channels depending on the initial vibrational state of the HeH+ and initial R0 separation. We find that several processes are induced by the dipole interaction. Among these, we find that the charge-transfer channel from the Li onto the ionic molecule HeH+ is the dominant outcome. Also, we find that a virtual photon dissociation process takes place via a dipole interaction that induces nuclear motion of the molecule through an electronic relaxation of the initial lithium 2p electron to the 2s state or to the 1s state of the He or H atom of the neighbor system, as well as vibrational intermolecular energy transfer. We report dissociation of the HeH+ molecule followed by chemical rearrangement leading to the formation of LiH and LiHe molecules and their respective charged ions. We find that deexcitation occurs on femtosecond while the molecular dissociation on picosecond time scales. Consequently, the dipole interaction between neighbors induces a richer dynamics.} | ||||||
BibTeX:
@article{Cabrera-Trujillo22,
author = {Cabrera-Trujillo, R. and Vendrell, O. and Cederbaum, L. S.},
title = {{Dipole-induced processes in HeH+ produced by an excited Li(2p) neighbor: From charge transfer to virtual photon dissociation, and formation of LiH and LiHe}},
journal = {Phys. Rev. A},
publisher = {American Physical Society},
year = {2022},
volume = {105},
issue = {5},
pages = {053104},
numpages = {11},
note = {theory},
doi = {https://doi.org/10.1103/PhysRevA.105.053104}
}
|
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| D.L. Andrews & D.S. Bradshaw | Controlling Electronic Energy Transfer: A Systematic Framework of Theory | 2022 | Appl. Sci. 12, 8597 |
|||
| Abstract: {The transport of electronic excitation energy (EET) between ions, atoms, molecules or chromophores is an important process that occurs in a wide range of physical systems. The tantalising prospect of effective experimental control over such transfer is, in principle, amenable to a variety of different kinds of approach. Several of the most promising, which are analysed and compared in this paper, involve the influence of externally applied static electric or electromagnetic fields, or the exploitation of local media effects. A quantum electrodynamical framework is used as a common basis to describe the corresponding mechanisms, illustrated by specially adapted Feynman diagrams. It becomes evident that energy transfer between polar species engages an additional pairwise interaction beyond the EET coupling. Such an effect may also play an important role in interatomic Coulombic decay (ICD), a process that has recently attracted fresh interest. The control of ICD, in which the photoionisation of two nearby atoms via energy transfer, is determined to have analogous characteristics to conventional forms of EET.} | ||||||
BibTeX:
@article{Andrews22,
author = {Andrews, D. L. and Bradshaw, D. S.},
title = {{Controlling Electronic Energy Transfer: A Systematic Framework of Theory}},
journal = {Appl. Sci.},
year = {2022},
volume = {12},
pages = {8597},
note = {theory},
doi = {https://doi.org/10.3390/app12178597}
}
|
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| N. Westerberg & R. Bennett | Perturbative light–matter interactions; from first principles to inverse design | 2023 | Phys. Rep. 1026, 1-63 |
|||
| Abstract: {Our experience of the world around us is governed almost entirely by light–matter interactions. At the most fundamental level, such interactions are described by quantum electrodynamics (QED), a well-established theory that has stood up to decades of experimental testing to remarkable degrees of precision. However, the complexity of real systems almost always means that the quantum electrodynamical equations describing a given scenario are often infeasible or impractical to solve. Thus, a sequence of approximations and idealisations are made, in order to build up from the simple case of an isolated electron interacting with a gauge field leading to the deceptively simple laws governing reflection and refraction at mirrors and lenses. This review provides a pedagogical overview of this journey, concentrating on cases where external boundary conditions can be used as a control method. Beginning from the fundamental Lagrangian, topics include gauge freedom, perturbative macroscopic QED descriptions of spontaneous decay, Casimir–Polder forces, resonant energy transfer, interatomic Coulombic decay, all of which are described in terms of the dyadic Green’s tensor that solves the Helmholtz equation. We discuss in detail how to calculate this tensor in practical situations before outlining new techniques in the design and optimisation of perturbative light–matter interactions, highlighting some recent advances in free-form, unconstrained inverse design of optical devices. Finally, an outlook towards the frontiers in the interaction of quantum light with matter is given, including its interface with chemical reactivity via polaritonic chemistry and quantum chemistry via quantum electrodynamical density functional theory (QEDFT).} | ||||||
BibTeX:
@article{Westerberg23,
author = {N. Westerberg and R. Bennett},
title = {{Perturbative light–matter interactions; from first principles to inverse design}},
journal = {Phys. Rep.},
year = {2023},
volume = {1026},
pages = {1-63},
note = {theory},
doi = {https://doi.org/10.1016/j.physrep.2023.07.005}
}
|
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| A.D. Skitnevskaya, K. Gokhberg, A.B. Trofimov, E.K. Grigoricheva, A.I. Kuleff & L.S. Cederbaum | Two-Sided Impact of Water on the Relaxation of Inner-Valence Vacancies of Biologically Relevant Molecules | 2023 | J. Phys. Chem. Lett. 14, 1418-1426 |
|||
| Abstract: {After ionization of an inner-valence electron of molecules, the resulting cation-radicals store substantial internal energy which, if sufficient, can trigger ejection of an additional electron in an Auger decay usually followed by molecule fragmentation. In the environment, intermolecular Coulombic decay (ICD) and electron-transfer mediated decay (ETMD) are also operative, resulting in one or two electrons being ejected from a neighbor, thus preventing the fragmentation of the initially ionized molecule. These relaxation processes are investigated theoretically for prototypical heterocycle–water complexes of imidazole, pyrrole, and pyridine. It is found that the hydrogen-bonding site of the water molecule critically influences the nature and energetics of the electronic states involved, opening or closing certain relaxation processes of the inner-valence ionized system. Our results indicate that the relaxation mechanisms of biologically relevant systems with inner-valence vacancies on their carbon atoms can strongly depend on the presence of the electron-density donating or accepting neighbor, either water or another biomolecule.} | ||||||
BibTeX:
@article{Skitnevskaya23,
author = {Skitnevskaya, A. D. and Gokhberg, K. and Trofimov, A. B. and Grigoricheva, E. K. and Kuleff, A. I. and Cederbaum, L. S.},
title = {{Two-Sided Impact of Water on the Relaxation of Inner-Valence Vacancies of Biologically Relevant Molecules}},
journal = {J. Phys. Chem. Lett.},
year = {2023},
volume = {14},
pages = {1418-1426},
note = {theory},
doi = {https://doi.org/10.1021/acs.jpclett.2c03654}
}
|
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| R. Shaik, H.R. Varma, M.E. Madjet, F. Zheng, T. Frauenheim & H.S. Chakraborty | Plasmonic Resonant Intercluster Coulombic Decay | 2023 | Phys. Rev. Lett. 130, 233201 |
|||
| Abstract: {Light-induced energy confinement in nanoclusters via plasmon excitations influences applications in nanophotonics, photocatalysis, and the design of controlled slow electron sources. The resonant decay of these excitations through the cluster’s ionization continuum provides a unique probe of the collective electronic behavior. However, the transfer of a part of this decay amplitude to the continuum of a second conjugated cluster may offer control and efficacy in sharing the energy nonlocally to instigate remote collective events. With the example of a spherically nested dimer Na20@C240 of two plasmonic systems we find that such a transfer is possible through the resonant intercluster Coulombic decay (RICD) as a fundamental process. This plasmonic RICD signal can be experimentally detected by the photoelectron velocity map imaging technique.} | ||||||
BibTeX:
@article{Shaik23,
author = {Shaik, R. and Varma, H. R. and Madjet, M. E. and Zheng, F. and Frauenheim, T. and Chakraborty, H. S.},
title = {{Plasmonic Resonant Intercluster Coulombic Decay}},
journal = {Phys. Rev. Lett.},
publisher = {American Physical Society},
year = {2023},
volume = {130},
issue = {23},
pages = {233201},
numpages = {7},
note = {theory},
doi = {https://doi.org/10.1103/PhysRevLett.130.233201}
}
|
||||||
| S. Remme, A.B. Voitkiv & C. Müller | Resonantly enhanced interatomic Coulombic electron capture in a system of three atoms | 2023 | J. Phys. B: At. Mol. Opt. Phys. 56, 095202 |
|||
| Abstract: {In interatomic Coulombic electron capture, the capture of a free electron at an atomic center is accompanied by the radiationless transfer of the excess energy to a neighboring atom of different species, leading to ionization of the latter. We show that this interatomic process can be strongly enhanced by the presence of an additional third atom, provided the energy of the free-bound capture transition in the first atom is resonant to a dipole-allowed excitation energy in this assisting atom. The relation of the resonantly enhanced three-center electron capture with other processes is discussed, and its dependencies on the incident electron energy and the spatial geometry of the triatomic system are illustrated.} | ||||||
BibTeX:
@article{Remme_2023,
author = {S Remme and A B Voitkiv and C Müller},
title = {{Resonantly enhanced interatomic Coulombic electron capture in a system of three atoms}},
journal = {J. Phys. B: At. Mol. Opt. Phys.},
publisher = {IOP Publishing},
year = {2023},
volume = {56},
pages = {095202},
note = {theory},
doi = {https://doi.org/10.1088/1361-6455/acc370}
}
|
||||||
| R. Kumar & N. Vaval | Effect of Protonation and Deprotonation on Electron Transfer Mediated Decay and Interatomic Coulombic Decay | 2023 | ChemPhysChem 24, e202200340 |
|||
| Abstract: {Abstract Electronically excited atoms or molecules in an environment are often subject to interatomic/intermolecular Coulombic decay (ICD) and/or electron transfer mediated decay (ETMD) mechanisms. A few of the numerous variables that can impact these non-radiative decay mechanisms include bond distance, the number of nearby atoms or molecules, and the polarisation effect. In this paper, we have studied the effect of protonation and deprotonation on the ionization potential (IP), double ionization potential (DIP), and lifetime (or decay width) of the temporary bound state in these non-radiative decay processes. We have chosen LiH-NH3 and LiH-H2O as test systems. The equation of motion coupled cluster singles and doubles method augmented by complex absorbing potential (CAP-EOM-CCSD) has been used in calculating the energetic position of the decaying state and the system's decay rate. Deprotonation of LiH-NH3/LiH-H2O either from the metal center (LiH) or from ammonia/water lowers the IP and DIP compared to the neutral systems. In contrast, protonation increases these quantities compared to neutral systems. The protonation closes the inner valence state relaxation channels for ICD/ETMD. For example, the decay of the O-2s/N-2s state stops in protonated systems (LiH2+-H2O, LiH2+-NH3, and LiH-NH4+). Our study also shows that the efficiency, i. e., the rate of ICD/ETMD, can be altered by protonation and deprotonation. It is expected to have implications for chemical and biological systems.} | ||||||
BibTeX:
@article{Kumar22_2,
author = {Kumar, R. and Vaval, N.},
title = {{Effect of Protonation and Deprotonation on Electron Transfer Mediated Decay and Interatomic Coulombic Decay}},
journal = {ChemPhysChem},
year = {2023},
volume = {24},
pages = {e202200340},
note = {theory},
doi = {https://doi.org/10.1002/cphc.202200340}
}
|
||||||
| S. Kazandjian, M. Kircher, G. Kastirke, J.B. Williams, M. Schöffler, M. Kunitski, R. Dörner, T. Miteva, S. Engin, F. Trinter, T. Jahnke & N. Sisourat | Interatomic Coulombic decay in small helium clusters | 2023 | Phys. Chem. Chem. Phys. 25, 25711-25719 |
|||
| Abstract: {Interatomic Coulombic decay (ICD) is an ultrafast non-radiative electronic decay process wherein an excited atom transfers its excess energy to a neighboring species leading to the ionization of the latter. In helium clusters, ICD can take place, for example, after simultaneous ionization and excitation of one helium atom within the cluster. After ICD, two helium ions are created and the system undergoes a Coulomb explosion. In this work, we investigate theoretically ICD in small helium clusters containing between two and seven atoms and compare our findings to two sets of coincidence measurements on clusters of different mean sizes. We provide a prediction on the lifetime of the excited dimer and show that ICD is faster for larger clusters. This is due to (i) the increased number of neighboring atoms (and therefore the number of decay channels) and (ii) the substantial decrease of the interatomic distances. In order to provide more details on the decay dynamics, we report on the kinetic-energy distributions of the helium ions. These distributions clearly show that the ions may undergo charge exchange with the neutral atoms within the cluster, such process is known as frustrated Coulomb explosion. The probability for these charge-exchange processes increases with the size of the clusters and is reflected in our calculated and measured kinetic-energy distributions. These distributions are therefore characteristics of the size distribution of small helium clusters.} | ||||||
BibTeX:
@article{Kazandjian23,
author = {Kazandjian, S. and Kircher, M. and Kastirke, G. and Williams, J. B. and Schöffler, M. and Kunitski, M. and Dörner, R. and Miteva, T. and Engin, S. and Trinter, F. and Jahnke, T. and Sisourat, N.},
title = {{Interatomic Coulombic decay in small helium clusters}},
journal = {Phys. Chem. Chem. Phys.},
publisher = {The Royal Society of Chemistry},
year = {2023},
volume = {25},
issue = {37},
pages = {25711-25719},
note = {theory},
doi = {https://doi.org/10.1039/D3CP02885B}
}
|
||||||
| N.K. Jayadev, W. Skomorowski & A.I. Krylov | Molecular-Orbital Framework of Two-Electron Processes: Application to Auger and Intermolecular Coulomb Decay | 2023 | J. Phys. Chem. Lett. 14, 8612-8619 |
|||
| Abstract: { States with core- or inner-shell vacancies, which are commonly created by absorption of high-energy photons, can decay by a two-electron process in which one electron fills the core hole and the second one is ejected. These processes accompany many X-ray spectroscopies. Depending on the nature of the initial core- or inner-shell-hole state and the decay valence-hole state, these processes are called Auger decay, intermolecular Coulomb decay, or electron-transfer-mediated decay. To connect many-body wave functions of the initial and final states with the molecular orbital picture of the decay, we introduce the concept of natural Auger orbitals (NAOs). NAOs are obtained by a two-step singular value decomposition of the two-body Dyson orbitals, reduced quantities that enter the expression of the decay rate in the Feshbach–Fano treatment. NAOs afford chemical insight and interpretation of the high-level ab initio calculations of Auger decay and related two-electron relaxation processes. } | ||||||
BibTeX:
@article{Jayadev23,
author = {Jayadev, N. K. and Skomorowski, W. and Krylov, A. I.},
title = {{Molecular-Orbital Framework of Two-Electron Processes: Application to Auger and Intermolecular Coulomb Decay}},
journal = {J. Phys. Chem. Lett.},
year = {2023},
volume = {14},
pages = {8612-8619},
note = {theory},
doi = {https://doi.org/10.1021/acs.jpclett.3c01966}
}
|
||||||
| J. Fedyk, K.l Gokhberg, T. Miteva, L.S. Cederbaum & A.I. Kuleff | Interference effects in the photoelectron spectrum of the NeKr dimer and vibrationally selected interatomic Coulombic decay | 2023 | Phys. Rev. A 107, 023109 |
|||
| Abstract: {n our work we study the interatomic Coulombic decay (ICD) in the NeKr dimer, where after 2s ionization of the Ne, the system relaxes and the excess energy is utilized to ionize the Kr. The temporal evolution of the ICD process in NeKr has been recently measured and theoretically explained by Trinter et al. [Chem. Sci. 13, 1789 (2022)]. Here we focus on two other main goals. The first goal regards the found interference effects in the photoemission (PE) spectrum, which are unusual phenomena in noble gas dimers. They result from the coherently excited vibrational energy levels and substantial dependence of the large ICD decay width on the internuclear distance. The PE spectrum reacts sensitively to changes in the potential energy curve (PEC) of the 2s ionized state, and we modified the available ab initio PEC in such a way that satisfactory agreement between theoretical and experimental data is achieved. The impact of isotope masses on the PE spectrum is briefly discussed and used in the determination of the PEC. Our second main goal concerns the nuclear motion during the ICD process. Here we investigate the impact of different vibrationally excited states of the electronic ground state on the ICD-electron and kinetic energy release (KER) spectra. To transfer our vibrationally selected ICD model to a realizable experiment, we also present the impact of temperature on the ICD-electron spectrum. Finally, our studies are complemented by comparing the directly computed KER spectrum to the mirror image of the ICD-electron spectrum, which coincide under certain conditions.} | ||||||
BibTeX:
@article{Fedyk23,
author = {Fedyk, J. and Gokhberg, K.l and Miteva, T. and Cederbaum, L. S. and Kuleff, A. I.},
title = {{Interference effects in the photoelectron spectrum of the NeKr dimer and vibrationally selected interatomic Coulombic decay}},
journal = {Phys. Rev. A},
publisher = {American Physical Society},
year = {2023},
volume = {107},
issue = {2},
pages = {023109},
numpages = {13},
note = {theory},
doi = {https://doi.org/10.1103/PhysRevA.107.023109}
}
|
||||||
| A. Bande, E. Fasshauer, A. Molle, D. Peláez, F.M. Pont & N. Sisourat | Interatomic Coulombic electron capture: the story so far | 2023 | J. Phys. B 56, 232001 |
|||
| Abstract: {Inter-particle Coulombic electron capture (ICEC) is an environment-enabled electron capture process by means of which a free electron can be efficiently attached to a system (e.g. ion, atom, molecule, or quantum dot (QD)). The excess electron attachment energy is simultaneously transferred to a neighbouring system which concomitantly undergoes ionization (or excitation). ICEC has been theoretically predicted in van-der-Waals and in hydrogen-bonded systems as well as in QD arrays. The theoretical approaches employed in these works range from analytical models to electronic structure and (quantum) dynamical calculations. In this article, we provide a comprehensive review of the main theoretical approaches that have been developed and employed to investigate ICEC and summarize the main conclusions learned from these works. Since knowledge on ICEC is still in its early stage, we conclude this review with our own views and proposals on the future perspectives for the research in ICEC.} | ||||||
BibTeX:
@article{Bande23,
author = {A. Bande and E. Fasshauer and A. Molle and D. Peláez and F. M Pont and N. Sisourat},
title = {{Interatomic Coulombic electron capture: the story so far}},
journal = {J. Phys. B},
publisher = {IOP Publishing},
year = {2023},
volume = {56},
pages = {232001},
note = {theory},
doi = {https://doi.org/10.1088/1361-6455/ad073c}
}
|
||||||
| Y.-S. Wang, J.X. Zhong Manis, M.C. Rohan, T.M. Orlando & J.S. Kretchmer | Modeling Intermolecular Coulombic Decay with Non-Hermitian Real-Time Time-Dependent Density Functional Theory | 2024 | J. Phys. Chem. Lett. 15, 7806-7813 |
|||
| Abstract: {In this work, we investigate the capability of using real-time time-dependent density functional theory (RT-TDDFT) in conjunction with a complex absorbing potential (CAP) to simulate the intermolecular Coulombic decay (ICD) processes following the ionization of an inner-valence electron. We examine the ICD dynamics in a series of noncovalent bonded dimer systems, including hydrogen-bonded and purely van der Waals (VdW)-bonded systems. In comparison to previous work, we show that RT-TDDFT simulations with a CAP correctly capture the ICD phenomenon in systems exhibiting a stronger binding energy. The calculated time scales for ICD of the studied systems are in the range of 5–50 fs, in agreement with previous studies. However, there is a breakdown in the accuracy of the methodology for the pure VdW-bonded systems. Overall, the presented RT-TDDFT/CAP methodology provides a powerful tool for differentiating between competing electronic relaxation pathways following inner-valence or core ionization without necessitating any a priori assumptions.} | ||||||
BibTeX:
@article{Wang24,
author = {Wang, Y.-S. and Zhong Manis, J. X. and Rohan, M. C. and Orlando, T. M. and Kretchmer, J. S.},
title = {{Modeling Intermolecular Coulombic Decay with Non-Hermitian Real-Time Time-Dependent Density Functional Theory}},
journal = {J. Phys. Chem. Lett.},
year = {2024},
volume = {15},
pages = {7806-7813},
note = {theory},
doi = {https://doi.org/10.1021/acs.jpclett.4c01146}
}
|
||||||
| M. Rana & A. Ghosh | Full Dynamical and Ab Initio Investigation of the Electron Transfer-Mediated Decay Mechanism of He2 in the Presence of Heavier Alkali Dimers | 2024 | J. Phys. Chem. A 128, 1973-1983 |
|||
| Abstract: { We have studied the electron transfer-mediated decay (ETMD) process for the 1s ionized state of the He atom in the presence of a heavier alkali homonuclear dimer (Na2, K2, and Rb2) as well as heteronuclear dimer (LiNa, NaK, and KRb). In our computation, we have considered all the alkali dimers being in the singlet electronic ground state. The electron transfer from the alkali dimer to He (1s-1) leads to the emission of another electron from the alkali dimer into the continuum. We have investigated the impact of the distance of the He atom from the center of mass of the alkali dimer on the ETMD decay width. We also performed the Born–Oppenheimer molecular dynamics simulation to understand the impact of nuclear dynamics on the ETMD process. } | ||||||
BibTeX:
@article{Rana24,
author = {Rana, M. and Ghosh, A.},
title = {{Full Dynamical and Ab Initio Investigation of the Electron Transfer-Mediated Decay Mechanism of He2 in the Presence of Heavier Alkali Dimers}},
journal = {J. Phys. Chem. A},
year = {2024},
volume = {128},
pages = {1973-1983},
note = {theory},
doi = {https://doi.org/10.1021/acs.jpca.3c07115}
}
|
||||||
| F.M. Pont, A. Bande, E. Fasshauer, A. Molle, D. Peláez & N. Sisourat | Impact of the nuclear motion on the interparticle Coulombic electron capture | 2024 | Phys. Rev. A 110, 042804 |
|||
| Abstract: {Interparticle Coulombic electron capture (ICEC) is an environment-enabled electron capture process by means of which a free electron can be efficiently attached to a system (i.e., ion, atom, molecule, or quantum dot). The excess electron attachment energy is simultaneously transferred to a neighboring system (the environment) which undergoes ionization. ICEC has been theoretically predicted in van der Waals and hydrogen bonded systems as well as in quantum dot arrays. The theoretical approaches employed in these works range from analytical models to ab initio electronic structure and dynamical calculations. A common assumption in these approaches is that nuclei remain fixed during ICEC. In this paper, we use full explicit electron-nuclear dynamics simulations to show that the relative nuclear motion between the two species involved in ICEC enables the electron attachment at kinetic energies of the incoming electron far below the vertical energy threshold (i.e., at the equilibrium geometry of the system). ICEC is therefore more efficient than expected.} | ||||||
BibTeX:
@article{Pont24,
author = {Pont, F. M. and Bande, A. and Fasshauer, E. and Molle, A. and Peláez, D. and Sisourat, N.},
title = {{Impact of the nuclear motion on the interparticle Coulombic electron capture}},
journal = {Phys. Rev. A},
publisher = {American Physical Society},
year = {2024},
volume = {110},
issue = {4},
pages = {042804},
numpages = {7},
note = {theory},
doi = {https://doi.org/10.1103/PhysRevA.110.042804}
}
|
||||||
| R. Kumar, A. Ghosh & N. Vaval | Relaxation of the 2a1 ionized water dimer: An interplay of intermolecular Coulombic decay (ICD) and proton transfer processes | 2024 | J. Chem. Phys. 160, 214302 |
|||
| Abstract: {This article investigates the relaxation dynamics of the ionized 2a1 state of a water molecule within a water dimer. The study was motivated by findings from two previous pieces of research that focused on the relaxation behaviors of the inner-valence ionized water dimer. The present study discloses an observation indicating that water dimers display specific fragmentation patterns following inner-valence ionization, depending on the position of the vacancy. Vacancies were created in the 2a1 state of the proton-donating water molecule (PDWM) and proton-accepting water molecule (PAWM). Utilizing Born–Oppenheimer molecular dynamics simulations, the propagation of the 2a1 ionized state was carried out for both scenarios. The results revealed proton transfer occurred when the vacancy resided in the PDWM, accompanied by the closing of decay channels for O–H bond distance (RO-H > 1.187 Å (matching Richter et al.’s findings). Conversely, when vacancy was on PAWM, we observed no closing of decay channels (aligning with Jahnke et al.’s findings). This difference translates to distinct fragmentation pathways. In PDWM cases, 2a1 state ionization leads to H3O2-OH· formation. In contrast, PAWM vacancies result in decay pathways leading to H2O+–H2O+ products.} | ||||||
BibTeX:
@article{Kumar24,
author = {Kumar, R. and Ghosh, A. and Vaval, N.},
title = {{Relaxation of the 2a1 ionized water dimer: An interplay of intermolecular Coulombic decay (ICD) and proton transfer processes}},
journal = {J. Chem. Phys.},
year = {2024},
volume = {160},
pages = {214302},
note = {theory},
doi = {https://doi.org/10.1063/5.0199888}
}
|
||||||
| S. Kim, S. Steinhäuser, A.B. Voitkiv & C. Müller | Two-center resonant photoionization-excitation driven by combined intra- and interatomic electron correlations | 2024 | J. Phys. B: At. Mol. Opt. Phys. 57, 035002 |
|||
| Abstract: {Ionization-excitation of an atom induced by the absorption of a single photon in the presence of a neighboring atom is studied. The latter is, first, resonantly photoexcited and, afterwards, transfers the excitation energy radiationlessly to the :other atom, leading to its ionization with simultaneous excitation. The process relies on the combined effects of interatomic and intraatomic electron correlations. Under suitable conditions, it can dominate by several orders of magnitude over direct photoionization-excitation and even over direct photoionization. In addition, we briefly discuss another kind of two-center resonant photoionization with excitation where the ionization and residual excitation in the final state are located at different atomic sites.} | ||||||
BibTeX:
@article{Kim24,
author = {S Kim and S Steinhäuser and A B Voitkiv and C Müller},
title = {{Two-center resonant photoionization-excitation driven by combined intra- and interatomic electron correlations}},
journal = {J. Phys. B: At. Mol. Opt. Phys.},
publisher = {IOP Publishing},
year = {2024},
volume = {57},
pages = {035002},
note = {theory},
doi = {https://doi.org/10.1088/1361-6455/ad23f6}
}
|
||||||
| J. Hofierka & L.S. Cederbaum | Core-hole jumping between heavy atoms enabled by retardation | 2024 | Phys. Rev. A 109, 052812 |
|||
| Abstract: {In interatomic Coulombic decay (ICD) an excited neutral atom or excited ion transfers its excess energy to ionize a neighboring atom. If the excitation or ionization involves valence electrons, the process is efficient (typically in the femtosecond regime), becomes more efficient the more neighbors are present, and often dominates all other relaxation processes. The situation changes when considering the excitation or ionization of core electrons. For light atoms, core-level ICD is inferior to Auger decay, but still a relevant relaxation pathway. For heavy atoms the excess energy is enormous and by consulting the usual asymptotic equation for the ICD rate one can only conclude the deep core-level ICD to be negligible. Retardation effects due to the finite speed of light strongly change the asymptotic behavior of the ICD rate, in particular for deep core levels. The impact of retardation is investigated in detail for deep core-level ICD. Several examples of heavy atoms undergoing ICD with heavy neighbors are explicitly studied and general conclusions are drawn.} | ||||||
BibTeX:
@article{Hofierka24,
author = {Hofierka, J. and Cederbaum, L. S.},
title = {{Core-hole jumping between heavy atoms enabled by retardation}},
journal = {Phys. Rev. A},
publisher = {American Physical Society},
year = {2024},
volume = {109},
issue = {5},
pages = {052812},
numpages = {5},
note = {theory},
doi = {https://doi.org/10.1103/PhysRevA.109.052812}
}
|
||||||
| V. Graves, J. Šenk, P. Kolorenč, N. Sisourat & J.D. Gorfinkiel | Virtual photon exchange vs electron transfer in interparticle Coulombic electron capture | 2024 | J. Chem. Phys. 160, 204306 |
|||
| Abstract: {We have investigated Interparticle Coulombic Electron Capture (ICEC) using an ab initio approach for two systems, H+ + H2O and H + H2O+. In this work, we have determined the contribution of virtual photon exchange and electron transfer to the total ICEC cross section as a function of the distance between the charged and neutral particles. Furthermore, we have shown that the relative orientation of the electron acceptor and neighbor systems affects the magnitude of the ICEC cross sections by at least two orders at relatively small distances. This geometry dependence, present even for distances as large as 10 a0, is due to the electron transfer contribution. The relative magnitude of each contribution to ICEC seems to depend on the system studied. By replacing the projectile electron with a positron, we have confirmed that electron transfer also takes place in positron collisions and that the charge of the projectile has a noticeable effect on the process, particularly at low scattering energies.} | ||||||
BibTeX:
@article{Graves24,
author = {Graves, V. and Šenk, J. and Kolorenč, P. and Sisourat, N. and Gorfinkiel, J. D.},
title = {{{Virtual photon exchange vs electron transfer in interparticle Coulombic electron capture}}},
journal = {J. Chem. Phys.},
year = {2024},
volume = {160},
pages = {204306},
note = {theory},
doi = {https://doi.org/10.1063/5.0203795}
}
|
||||||
| L.S. Cederbaum & A.I. Kuleff | An ensemble of excited molecules collectively emits multiple-frequency real and virtual photons | 2024 | J. Chem. Phys. 160, 064306 |
|||
| Abstract: {{The interplay of molecules gives rise to collective phenomena absent in a single molecule. Many examples of collective phenomena have been reported as their knowledge is essential for understanding the behavior of matter. Here, we consider molecules sufficiently separated from each other to not form chemical bonds. If these molecules are excited, e.g., by a weak laser, can they concertedly relax by emitting a single high-energy photon possessing the total energy of all the relaxing molecules? We show that this concerted emission process is indeed possible. We estimate its probability and analyze its dependence on molecular properties, intermolecular distances, and relative orientations of the molecules. A numerical example on two pyridine molecules is given. The concerted emission found is a fundamental process expected to be operative in gas phase and clusters. Its true relevance lies in its intimate relationship to concerted emission of virtual photons and thus to collective energy transfer ionizing neighboring systems. The estimated rates and examples discussed of this collective intermolecular Coulombic decay shed much light on recent puzzling experiments.}} | ||||||
BibTeX:
@article{Cederbaum24,
author = {Cederbaum, L. S. and Kuleff, A. I.},
title = {{{An ensemble of excited molecules collectively emits multiple-frequency real and virtual photons}}},
journal = {J. Chem. Phys.},
year = {2024},
volume = {160},
pages = {064306},
note = {theory},
doi = {https://doi.org/10.1063/5.0184737}
}
|
||||||
| L.S. Cederbaum & A.I. Kuleff | Stimulated Emission of Virtual Photons: Energy Transfer by Light | 2024 | J. Phys. Chem. Lett. 15, 7357-7362 |
|||
| Abstract: { Energy-transfer processes can be viewed as being due to the emission of a virtual photon. It is demonstrated that the emission of virtual photons and thus of energy transfer is stimulated by the sheer presence of photons. We concentrate here on interatomic/intermolecular Coulombic decay (ICD) where an excited system relaxes by transferring its excess energy to a neighbor ionizing it. ICD is inactive if this excess energy is insufficiently large. However, in the presence of photons, the long-range interaction between the system and its neighbor can utilize the photon field making ICD active. The properties of this stimulated-ICD mechanism are discussed. The concept can be transferred to other scenarios. We discuss collective-ICD where two excited molecules concertedly transfer their excess energy. Also here, the presence of photons can make the process active if the sum of excess energies were insufficient to do so. Examples with typical molecules ahysRevA.110.04280nd atoms are presented to demonstrate that these stimulated processes can play a role. } | ||||||
BibTeX:
@article{Cederbaum24_2,
author = {Cederbaum, L. S. and Kuleff, A. I.},
title = {{Stimulated Emission of Virtual Photons: Energy Transfer by Light}},
journal = {J. Phys. Chem. Lett.},
year = {2024},
volume = {15},
pages = {7357-7362},
note = {theory},
doi = {https://doi.org/10.1021/acs.jpclett.4c01191}
}
|
||||||
| R. Feifel, J.H.D. Eland, L. Storchi & F. Tarantelli | Complete valence double photoionization of SF6 | 2005 | J. Chem. Phys. 122, 144309 |
|||
| Abstract: {Single photon double ionization of SF6 has been investigated at the photon energies 38.71, 40.814, and 48.372 eV by using a recently developed time-of-flight photoelectron-photoelectron coincidence spectroscopy technique which gives complete two-dimensional e--e- spectra. The first complete single photon double ionization electron spectrum of SF6 up to a binding energy of ~48 eV is presented and accurately interpreted with the aid of Green's function ADC(2) calculations. Spectra which reflect either mainly direct or mainly indirect (via interatomic coulombic decay of F 2s holes) double ionization of SF6 are extracted from the coincidence map and discussed. A previous, very low value for the onset of double ionization of SF6 is found to energetically coincide with a peak structure related to secondary inelastic scattering events.} | ||||||
BibTeX:
@article{Feifel05,
author = {Feifel, R. and Eland, J.H.D. and Storchi, L. and Tarantelli, F.},
title = {{Complete valence double photoionization of SF6}},
journal = {J. Chem. Phys.},
publisher = {AIP},
year = {2005},
volume = {122},
issue = {14},
pages = {144309},
numpages = {9},
note = {experiment & theory},
doi = {https://doi.org/10.1063/1.1872837}
}
|
||||||
| R.C. Bilodeau, C.W. Walter, I. Dumitriu, N.D. Gibson, G.D. Ackerman, J.D. Bozek, B.S. Rude, R. Santra, L.S. Cederbaum & N. Berrah | Photo double detachment of CN-: Electronic decay from an inner-valence hole in molecular anions | 2006 | Chem. Phys. Lett. 426, 237 |
|||
| Abstract: {The first measurements of inner-valence photodetachment from a molecular negative ion are presented. Experimental and theoretical studies of CN- photodetachment around the 2-electron threshold (25-90 eV) are reported. Included are measured absolute cross sections for CN+ production by photo double detachment of CN-, and for C+ and N+ fragments produced from the dissociation of the excited molecule. The measurements also reveal the signature of inner-valence autoionization, similar to the interatomic Coulombic decay (ICD) phenomenon. This work confirms the predicted effect, which should in general be present for molecular anions, even in very small molecules.} | ||||||
BibTeX:
@article{Bilodeau06,
author = {Bilodeau, R. C. and Walter, C. W. and Dumitriu, I. and Gibson, N. D. and Ackerman, G. D. and Bozek, J. D. and Rude, B. S. and Santra, R. and Cederbaum, L. S. and Berrah, N.},
title = {{Photo double detachment of CN-: Electronic decay from an inner-valence hole in molecular anions}},
journal = {Chem. Phys. Lett.},
publisher = {Elsevier},
year = {2006},
volume = {426},
issue = {4--6},
pages = {237},
numpages = {5},
note = {experiment & theory},
doi = {https://doi.org/10.1016/j.cplett.2006.05.127}
}
|
||||||
| X.-J. Liu, N. Saito, H. Fukuzawa, Y. Morishita, S. Stoychev, A. Kuleff, I.H. Suzuki, Y. Tamenori, R. Richter, G. Prümper & K. Ueda | Evidence of sequential interatomic decay in argon trimers obtained by electron-triple-ion coincidence spectroscopy | 2007 | J. Phys. B: At. Mol. Opt. Phys. 40, F1 |
|||
| Abstract: {Sequential interatomic decay, where the first step is an Auger decay with interatomic character and the second step is a pure interatomic Coulombic decay (ICD), is identified in Ar trimers Ar3. The 2p hole state in Ar3 decays via the L2,3M1M2,3 Auger to the one-site two-hole states Ar++(3s-13p-1)-Ar-Ar that couples to the two-site satellite states Ar+(3p-2nl)-Ar+(3p-1)-Ar. These states are subject to ICD to the states Ar+(3p-1)-Ar+(3p-1)-Ar+(3p-1), in which the nl electron fills the 3p hole in the same Ar site and one of the 3p electrons in the third Ar site is emitted as a slow ICD electron. This ICD process is identified unambiguously by electron-ion-ion-ion coincidence spectroscopy in which the kinetic energy of the slow ICD electron and the kinetic energy release among the three Ar+ ions are measured in coincidence.} | ||||||
BibTeX:
@article{Liu07,
author = {Liu, X.-J. and Saito, N. and Fukuzawa, H. and Morishita, Y. and Stoychev, S. and Kuleff, A. and Suzuki, I. H. and Tamenori, Y. and Richter, R. and Prümper, G. and Ueda, K.},
title = {{Evidence of sequential interatomic decay in argon trimers obtained by electron-triple-ion coincidence spectroscopy}},
journal = {J. Phys. B: At. Mol. Opt. Phys.},
publisher = {IOP},
year = {2007},
volume = {40},
issue = {1},
pages = {F1},
numpages = {7},
note = {experiment & theory},
doi = {https://doi.org/10.1088/0953-4075/40/1/F01}
}
|
||||||
| A.S. Sandhu, E. Gagnon, R. Santra, V. Sharma, W. Li, Ph. Ho, P. Ranitovic, C.L. Cocke, M.M. Murnane & H.C. Kapteyn | Observing the Creation of Electronic Feshbach Resonances in Soft X-ray-Induced O2 Dissociation | 2008 | Science 322, 1081 |
|||
| Abstract: {When an atom or molecule is ionized by an x-ray, highly excited states can be created that then decay, or autoionize, by ejecting a second electron from the ion. We found that autoionization after soft x-ray photoionization of molecular oxygen follows a complex multistep process. By interrupting the autoionization process with a short laser pulse, we showed that autoionization cannot occur until the internuclear separation of the fragments is greater than approximately 30 angstroms. As the ion and excited neutral atom separated, we directly observed the transformation of electronically bound states of the molecular ion into Feshbach resonances of the neutral oxygen atom that are characterized by both positive and negative binding energies. States with negative binding energies have not previously been predicted or observed in neutral atoms.} | ||||||
BibTeX:
@article{Sandhu08,
author = {Sandhu, A. S. and Gagnon, E. and Santra, R. and Sharma, V. and Li, W. and Ho, Ph. and Ranitovic, P. and Cocke, C. L. and Murnane, M. M. and Kapteyn, H. C.},
title = {{Observing the Creation of Electronic Feshbach Resonances in Soft X-ray-Induced O2 Dissociation}},
journal = {Science},
publisher = {Science},
year = {2008},
volume = {322},
issue = {5904},
pages = {1081},
numpages = {5},
note = {experiment & theory},
doi = {https://doi.org/10.1126/science.1164498}
}
|
||||||
| K. Kreidi, T. Jahnke, Th. Weber, T. Havermeier, X. Liu, Y. Morisita, S. Schössler, L. Ph.H. Schmidt, M. Schöffler, M. Odenweller, N. Neumann, L. Foucar, J. Titze, B. Ulrich, F. Sturm, C. Stuck, R. Wallauer, S. Voss, I. Lauter, H.K. Kim, M. Rudloff, H. Fukuzawa, G. Prümper, N. Saito, K. Ueda, A. Czasch, O. Jagutzki, H. Schmidt-Böcking, S. Stoychev, Ph.V. Demekhin & R. Dörner | Relaxation processes following 1s photoionization and Auger decay in Ne2 | 2008 | Phys. Rev. A 78, 043422 |
|||
| Abstract: {We used cold target recoil ion momentum spectroscopy for a comprehensive study of the decay of a neon dimer (Ne2) after removal of a 1s electron from one of the atoms of the dimer. Multiple decay pathways are found and identified, mostly being connected to different types of interatomic Coulombic decay (ICD) such as the “direct” ICD which happens via the transfer of a virtual photon, the “exchange” ICD via an electron transfer and the electron transfer mediated decay. A quantitative theoretical analysis of these decay processes can be found in the preceding paper by Demekhin et al. [Phys. Rev. A 78, 043421 (2008)], as well as in Stoychev et al. [J. Chem. Phys. 129, 074307 (2008)].} | ||||||
BibTeX:
@article{Kreidi08_2,
author = {Kreidi, K. and Jahnke, T. and Weber, Th. and Havermeier, T. and Liu, X. and Morisita, Y. and Schössler, S. and Schmidt, L.Ph.H. and Schöffler, M. and Odenweller, M. and Neumann, N. and Foucar, L. and Titze, J. and Ulrich, B. and Sturm, F. and Stuck, C. and Wallauer, R. and Voss, S. and Lauter, I. and Kim, H. K. and Rudloff, M. and Fukuzawa, H. and Prümper, G. and Saito, N. and Ueda, K. and Czasch, A. and Jagutzki, O. and Schmidt-Böcking, H. and Stoychev S. and Demekhin, Ph. V. and Dörner, R.},
title = {{Relaxation processes following 1s photoionization and Auger decay in Ne2}},
journal = {Phys. Rev. A},
publisher = {American Physical Society},
year = {2008},
volume = {78},
issue = {4},
pages = {043422},
numpages = {9},
note = {experiment & theory},
doi = {https://doi.org/10.1103/PhysRevA.78.043422}
}
|
||||||
| W. Pokapanich, H. Bergersen, I.L. Bradeanu, R.R.T. Marinho, A. Lindblad, S. Legendre, A. Rosso, S. Svensson, O. Björneholm, M. Tchaplyguine, G. Öhrwall, N.V. Kryzhevoi & L.S. Cederbaum | Auger Electron Spectroscopy as a Probe of the Solution of Aqueous Ions | 2009 | J. Am. Chem. Soc. 131, 7264 |
|||
| Abstract: {Aqueous potassium chloride has been studied by synchrotron-radiation excited core-level photoelectron and Auger electron spectroscopy. In the Auger spectrum of the potassium ion, the main feature comprises the final states where two outer valence holes are localized on potassium. This spectrum exhibits also another feature at a higher kinetic energy which is related to final states where outer valence holes reside on different subunits. Through ab initio calculations for microsolvated clusters, these subunits have been assigned as potassium ions and the surrounding water molecules. The situation is more complicated in the Auger spectrum of the chloride anion. One-center and multicenter final states are present here as well but overlap energetically.} | ||||||
BibTeX:
@article{Pokapanich09,
author = {Pokapanich, W. and Bergersen, H. and Bradeanu, I. L. and Marinho, R.R.T. and Lindblad, A. and Legendre, S. and Rosso, A. and Svensson, S. and Björneholm, O. and Tchaplyguine, M. and Öhrwall, G. and Kryzhevoi, N. V. and Cederbaum, L. S.},
title = {{Auger Electron Spectroscopy as a Probe of the Solution of Aqueous Ions}},
journal = {J. Am. Chem. Soc.},
publisher = {American Chemical Society},
year = {2009},
volume = {131},
issue = {21},
pages = {7264},
numpages = {8},
note = {experiment & theory},
doi = {https://doi.org/10.1021/ja8096866}
}
|
||||||
| K. Kreidi, Ph.V. Demekhin, T. Jahnke, Th. Weber, T. Havermeier, X. Liu, Y. Morisita, S. Schössler, L. Ph.H. Schmidt, M. Schöffler, M. Odenweller, N. Neumann, L. Foucar, J. Titze, B. Ulrich, F. Sturm, C. Stuck, R. Wallauer, S. Voss, I. Lauter, H.K. Kim, M. Rudloff, H. Fukuzawa, G. Prümper, N. Saito, K. Ueda, A. Czasch, O. Jagutzki, H. Schmidt-Böcking, S. Scheit, L.S. Cederbaum & R. Dörner | Photo- and Auger-Electron Recoil Induced Dynamics of Interatomic Coulombic Decay | 2009 | Phys. Rev. Lett. 103, 033001 |
|||
| Abstract: {At photon energies near the Ne K edge it is shown that for 1s ionization the Auger electron, and for 2s ionization the fast photoelectron, launch vibrational wave packets in a Ne dimer. These wave packets then decay by emission of a slow electron via interatomic Coulombic decay (ICD). The measured and computed ICD electron spectra are shown to be significantly modified by the recoil induced nuclear motion.} | ||||||
BibTeX:
@article{Kreidi09,
author = {Kreidi, K. and Demekhin, Ph. V. and Jahnke, T. and Weber, Th. and Havermeier, T. and Liu, X. and Morisita, Y. and Schössler, S. and Schmidt, L.Ph.H. and Schöffler, M. and Odenweller, M. and Neumann, N. and Foucar, L. and Titze, J. and Ulrich, B. and Sturm, F. and Stuck, C. and Wallauer, R. and Voss, S. and Lauter, I. and Kim, H. K. and Rudloff, M. and Fukuzawa, H. and Prümper, G. and Saito, N. and Ueda, K. and Czasch, A. and Jagutzki, O. and Schmidt-Böcking, H. and Scheit, S. and Cederbaum, L. S. and Dörner, R.},
title = {{Photo- and Auger-Electron Recoil Induced Dynamics of Interatomic Coulombic Decay}},
journal = {Phys. Rev. Lett.},
publisher = {American Physical Society},
year = {2009},
volume = {103},
issue = {3},
pages = {033001},
numpages = {4},
note = {experiment & theory},
doi = {https://doi.org/10.1103/PhysRevLett.103.033001}
}
|
||||||
| A. Yagishita, J. Adachi & M. Yamazaki | Photoemission dynamics in the molecular frame | 2010 | J. Phys.: Conf. Ser. 212, 012010 |
|||
| Abstract: {Photoemission dynamics, based on the molecular frame photoelectron angular distribution, is reported. In the fast decay channel leading to Ne+ + Ne2+ of Ne2 dimer, the molecular frame photoelectron measurements have been realized, and the core-hole localization observed. However, in the slow decay channel leading to Ne+ + Ne+, such measurements have not been applicable as expected. The molecular frame photoemission study has been extended to a non-axially symmetric H2O molecule, and its experimental result has been well explained by a simple scattering model which is widely used in surface science} | ||||||
BibTeX:
@proceedings{Yagishita10,
author = {Yagishita, A. and Adachi, J. and Yamazaki, M.},
title = {{Photoemission dynamics in the molecular frame}},
journal = {J. Phys.: Conf. Ser.},
series= {International Symposium on (e,2e), Double Photoionization and Related Topics & 15th International Symposium on Polarization and Correlation in Electronic and Atomic Collisions},
publisher = {IOP},
year = {2010},
volume = {212},
pages = {012010},
numpages = {6},
note = {experiment & theory},
doi = {https://doi.org/10.1088/1742-6596/212/1/012010}
}
|
||||||
| N. Sisourat, H. Sann, N.V. Kryzhevoi, P. Kolorenč, T. Havermeier, F. Sturm, T. Jahnke, H.-K. Kim, R. Dörner & L.S. Cederbaum | Interatomic electronic decay driven by nuclear motion | 2010 | Phys. Rev. Lett. 105, 173401 |
|||
| Abstract: {The interatomic electronic decay after inner-valence ionization of a neon atom by a single photon in a neon-helium dimer is investigated. The excited neon atom relaxes via interatomic Coulombic decay and the excess energy is transferred to the helium atom and ionizes it. We show that the decay process is only possible if the dimer's bond stretches up to 6.2 Å, i.e., to more than twice the equilibrium interatomic distance of the neutral dimer. Thus, it is demonstrated that the electronic decay, taking place at such long distances, is driven by the nuclear motion.} | ||||||
BibTeX:
@article{Sisourat10_3,
author = {Sisourat, N. and Sann, H. and Kryzhevoi, N. V. and Kolorenč, P. and Havermeier, T. and Sturm, F. and Jahnke, T. and Kim, H.-K. and Dörner, R. and Cederbaum, L. S.},
title = {{Interatomic electronic decay driven by nuclear motion}},
journal = {Phys. Rev. Lett.},
publisher = {American Physical Society},
year = {2010},
volume = {105},
issue = {17},
pages = {173401},
numpages = {4},
note = {experiment & theory},
doi = {https://doi.org/10.1103/PhysRevLett.105.173401}
}
|
||||||
| N. Sisourat, N.V. Kryzhevoi, P. Kolorenč, S. Scheit, T. Jahnke & L.S. Cederbaum | Ultralong-range energy transfer by interatomic Coulombic decay in an extreme quantum system | 2010 | Nat. Phys. 6, 508 |
|||
| Abstract: {When an atom is electronically excited, it relaxes by emitting a photon or an electron. These carry essential information on the electronic structure of their emitter. However, if an atom is embedded in a chemical environment, another ultrafast non-radiative decay process called interatomic Coulombic decay (ICD) can become operative. As ICD occurs only in the presence of neighbours, it is highly sensitive to that environment. Therefore, it has the potential to become a powerful spectroscopic method to probe the close environment of a system. ICD has been observed experimentally in van der Waals clusters as well as in hydrogen-bonded systems. A key feature of ICD is that the excited atom can transfer its excess energy to its neighbours over large distances. The giant extremely weakly bound helium dimer is a perfect candidate to investigate how far two atoms can exchange energy. We report here that the two helium atoms within the dimer can exchange energy by ICD over distances of more than 45 times their atomic radius. Moreover, we demonstrate that ICD spectroscopy can be used for imaging vibrational wavefunctions of the ionized-excited helium dimer.} | ||||||
BibTeX:
@article{Sisourat10_1,
author = {Sisourat, N. and Kryzhevoi, N. V. and Kolorenč, P. and Scheit, S. and Jahnke, T. and Cederbaum, L. S.},
title = {{Ultralong-range energy transfer by interatomic Coulombic decay in an extreme quantum system}},
journal = {Nat. Phys.},
publisher = {Nature Research},
year = {2010},
volume = {6},
pages = {508},
numpages = {4},
note = {experiment & theory},
doi = {https://doi.org/10.1038/NPHYS1685}
}
|
||||||
| K. Kreidi, T. Jahnke, T.H. Weber, T. Havermeier, R.E. Grisenti, X. Liu, Y. Morisita, S. Schössler, L. Ph.H. Schmidt, M. Schöffler, M. Odenweller, N. Neumann, L. Foucar, J. Titze, B. Ulrich, F. Sturm, C. Stuck, R. Wallauer, S. Voss, I. Lauter, H.K. Kim, M. Rudloff, H. Fukuzawa, G. Prümper, N. Saito, K. Ueda, A. Czasch, O. Jagutzki, H. Schmidt-Böcking, S.K. Semenov, N.A. Cherepkov & R. Dörner | Localization of inner shell photoelectron emission and interatomic Coulombic decay in neon dimers | 2010 | J. Phys.: Conf. Ser. 212, 012007 |
|||
| Abstract: {By using the COLd Target Recoil Ion Momentum Spectroscopy (COLTRIMS) we have investigated the 1s photoionization of neon dimers. Interatomic Coulombic Decay (ICD) takes place in the asymmetric charge breakup Ne2+/Ne1+. This breakup is used to determine whether the inner shell vacancies, resulting out of the photoionization of the dimer, and the valence shell vacancies, resulting out of the ICD, are localized at one of the atoms or delocalized over the two equivalent sites of the neon dimer.} | ||||||
BibTeX:
@proceedings{Kreidi10,
author = {Kreidi, K. and Jahnke, T. and Weber, T. H. and Havermeier, T. and Grisenti, R. E. and Liu, X. and Morisita, Y. and Schössler, S. and Schmidt, L.Ph.H. and Schöffler, M. and Odenweller, M. and Neumann, N. and Foucar, L. and Titze, J. and Ulrich, B. and Sturm, F. and Stuck, C. and Wallauer, R. and Voss, S. and Lauter, I. and Kim, H. K. and Rudloff, M. and Fukuzawa, H. and Prümper, G. and Saito, N. and Ueda, K. and Czasch, A. and Jagutzki, O. and Schmidt-Böcking, H. and Semenov, S. K. and Cherepkov, N. A. and Dörner, R.},
title = {{Localization of inner shell photoelectron emission and interatomic Coulombic decay in neon dimers}},
journal = {J. Phys.: Conf. Ser.},
series= {International Symposium on (e,2e), Double Photoionization and Related Topics & 15th International Symposium on Polarization and Correlation in Electronic and Atomic Collisions},
publisher = {IOP},
year = {2010},
volume = {212},
pages = {012007},
numpages = {5},
note = {experiment & theory},
doi = {https://doi.org/10.1088/1742-6596/212/1/012007}
}
|
||||||
| T. Havermeier, K. Kreidi, R. Wallauer, S. Voss, M. Schöffler, S. Schössler, L. Foucar, N. Neumann, J. Titze, H. Sann, M. Kühnel, J. Voigtsberger, N. Sisourat, W. Schöllkopf, H. Schmidt-Böcking, R.E. Grisenti, R. Dörner & T. Jahnke | Angular distributions of photoelectrons and interatomic-Coulombic-decay electrons from helium dimers: Strong dependence on the internuclear distance | 2010 | Phys. Rev. A 82, 063405 |
|||
| Abstract: {In the present paper we show, that the absorption of a single photon can singly ionize both atoms of a helium dimer (He2+): ionization with simultaneous excitation of one atom followed by deexcitation via Interatomic Coulombic Decay leads to the ejection of an electron from each of the the two atoms of the dimer. Using the COLTRIMS technique we obtained angular distributions of these electrons in the laboratory frame and in the molecular frame. We observe a pronounced variation of these distributions for different regions of kinetic energy releases of the ions.} | ||||||
BibTeX:
@article{Havermeier10_2,
author = {Havermeier, T. and Kreidi, K. and Wallauer, R. and Voss, S. and Schöffler, M. and Schössler, S. and Foucar, L. and Neumann, N. and Titze, J. and Sann, H. and Kühnel, M. and Voigtsberger, J. and Sisourat, N. and Schöllkopf, W. and Schmidt-Böcking, H. and Grisenti, R. E. and Dörner, R. and Jahnke, T. },
title = {{Angular distributions of photoelectrons and interatomic-Coulombic-decay electrons from helium dimers: Strong dependence on the internuclear distance}},
journal = {Phys. Rev. A},
publisher = {American Physical Society},
year = {2010},
volume = {82},
issue = {6},
pages = {063405},
numpages = {5},
note = {experiment & theory},
doi = {https://doi.org/10.1103/PhysRevA.82.063405}
}
|
||||||
| J. Titze, M. Schöffler, H.K. Kim, F. Trinter, M. Waitz, J. Voigtsberger, N. Neumann, B. Ulrich, K. Kreidi, R. Wallauer, M. Odenweller, T. Havermeier, S. Schössler, M. Meckel, L. Foucar, T. Jahnke, A. Czasch, L. Ph.H. Schmidt, O. Jagutzki, R.E. Grisenti, H. Schmidt-Böcking, H.J. Lüdde & R. Dörner | Ionization dynamics of helium dimers in fast collisions with He++ | 2011 | Phys. Rev. Lett. 106, 033201 |
|||
| Abstract: {By employing the cold target recoil ion momentum spectroscopy technique, we have investigated the (He+, He+) breakup of a helium dimer (He2) caused by transfer ionization and double capture in collisions with alpha particles (E = 150 keV/u). Surprisingly, the results show a two-step process as well as an one-step process followed by electron exchange. In addition, interatomic Coulombic decay [L. S. Cederbaum, J. Zobeley, and F. Tarantelli, Phys. Rev. Lett. 79, 4778 (1997).] is observed in an ion collision for the first time.} | ||||||
BibTeX:
@article{Titze11,
author = {Titze, J. and Schöffler, M. and Kim, H. -K. and Trinter, F. and Waitz, M. and Voigtsberger, J. and Neumann, N. and Ulrich, B. and Kreidi, K. and Wallauer, R. and Odenweller, M. and Havermeier, T. and Schössler, S. and Meckel, M. and Foucar, L. and Jahnke, T. and Czasch, A. and Schmidt, L.Ph.H. and Jagutzki, O. and Grisenti, R. E. and Schmidt-Böcking, H. and Lüdde, H. J. and Dörner, R.},
title = {{Ionization dynamics of helium dimers in fast collisions with He++}},
journal = {Phys. Rev. Lett.},
publisher = {American Physical Society},
year = {2011},
volume = {106},
issue = {3},
pages = {033201},
numpages = {4},
note = {experiment & theory},
doi = {https://doi.org/10.1103/PhysRevLett.106.033201}
}
|
||||||
| K. Sakai, S. Stoychev, T. Ouchi, I. Higuchi, M. Schöffler, T. Mazza, H. Fukuzawa, K. Nagaya, M. Yao, Y. Tamenori, A.I. Kuleff, N. Saito & K. Ueda | Electron-transfer-mediated decay and interatomic coulombic decay from the triply ionized states in argon dimers | 2011 | Phys. Rev. Lett. 106, 033401 |
|||
| Abstract: {We report the first observation of electron-transfer-mediated decay (ETMD) and interatomic Coulombic decay (ICD) from the triply charged states with an inner-valence vacancy, using the Ar dimer as an example. These ETMD and ICD processes, which lead to fragmentation of Ar3+-Ar into Ar2+-Ar2+ and Ar3+-Ar+, respectively, are unambiguously identified by electron-ion-ion coincidence spectroscopy in which the kinetic energy of the ETMD or ICD electron and the kinetic energy release between the two fragment ions are measured in coincidence.} | ||||||
BibTeX:
@article{Sakai11,
author = {Sakai, K. and Stoychev, S. and Ouchi, T. and Higuchi, I. and Schöffler, M. and Mazza, T. and Fukuzawa, H. and Nagaya, K. and Yao, M. and Tamenori, Y. and Kuleff, A. I. and Saito, N. and Ueda, K.},
title = {{Electron-transfer-mediated decay and interatomic coulombic decay from the triply ionized states in argon dimers}},
journal = {Phys. Rev. Lett.},
publisher = {American Physical Society},
year = {2011},
volume = {106},
issue = {3},
pages = {033401},
numpages = {4},
note = {experiment & theory},
doi = {https://doi.org/10.1103/PhysRevLett.106.033401}
}
|
||||||
| W. Pokapanich, N.V. Kryzhevoi, N. Ottosson, S. Svensson, L.S. Cederbaum, G. Öhrwall & O. Björneholm | Ionic-charge dependence of the intermolecular Coulombic decay time-scale for aqueous ions probed by the core-hole clock | 2011 | J. Am. Chem. Soc. 133, 13430 |
|||
| Abstract: {Auger electron spectroscopy combined with theoretical calculations have been applied to investigate the decay of the Ca 2p core hole of aqueous Ca2+. Beyond the localized two-hole final states on the calcium ion, originating from a normal Auger process, we have further identified the final states delocalized between the calcium ion and its water surroundings and produced by core level intermolecular Coulombic decay (ICD) processes. By applying the core-hole clock method, the time scale of the core level ICD was determined to be 33±1 fs for the 2p core hole of the aqueous Ca2+. The comparison of this time constant to those associated with the aqueous K+, Na+, Mg2+, and Al3+ ions reveals differences of one and up to two orders of magnitude. Such large variations in the characteristic time scales of the core level ICD processes is qualitatively explained by different internal decay mechanisms in different ions as well as by different ion-solvent distances and interactions.} | ||||||
BibTeX:
@article{Pokapanich11_1,
author = {Pokapanich, W. and Kryzhevoi, N. V. and Ottosson, N. and Svensson, S. and Cederbaum, L. S. and Öhrwall, G. and Björneholm, O.},
title = {{Ionic-charge dependence of the intermolecular Coulombic decay time-scale for aqueous ions probed by the core-hole clock}},
journal = {J. Am. Chem. Soc.},
publisher = {American Chemical Society},
year = {2011},
volume = {133},
issue = {34},
pages = {13430},
numpages = {7},
note = {experiment & theory},
doi = {https://doi.org/10.1021/ja203430s}
}
|
||||||
| T. Ouchi, K. Sakai, H. Fukuzawa, X.-J. Liu, I. Higuchi, Y. Tamenori, K. Nagaya, H. Iwayama, M. Yao, D. Zhang, D. Ding, A.I. Kuleff, S.D. Stoychev, Ph.V. Demekhin, N. Saito & K. Ueda | Three-electron interatomic coulombic decay from the inner-valence double-vacancy states in NeAr | 2011 | Phys. Rev. Lett. 107, 053401 |
|||
| Abstract: {We have unambiguously identified interatomic Coulombic decay (ICD) in NeAr from the inner-valence double-vacancy state Ne-Ar2+(3s-2) to outer-valence triple-vacancy states Ne+(2p-1)-Ar2+(3p-2) by momentum-resolved electron-ion multicoincidence. This is the first observation of ICD where three electrons (3e) participate in. The results suggest that this 3e ICD is significantly faster than other competing processes like fluorescence decay and charge transfer via curve crossing.} | ||||||
BibTeX:
@article{Ouchi11_2,
author = {Ouchi, T. and Sakai, K. and Fukuzawa, H. and Liu, X.-J. and Higuchi, I. and Tamenori, Y. and Nagaya, K. and Iwayama, H. and Yao, M. and Zhang, D. and Ding, D. and Kuleff, A. I. and Stoychev, S. D. and Demekhin, Ph. V. and Saito, N. and Ueda, K.},
title = {{Three-electron interatomic coulombic decay from the inner-valence double-vacancy states in NeAr}},
journal = {Phys. Rev. Lett.},
publisher = {American Physical Society},
year = {2011},
volume = {107},
issue = {5},
pages = {053401},
numpages = {4},
note = {experiment & theory},
doi = {https://doi.org/10.1103/PhysRevLett.107.053401}
}
|
||||||
| T. Ouchi, K. Sakai, H. Fukuzawa, I. Higuchi, Ph.V. Demekhin, Y.-C. Chiang, S.D. Stoychev, A.I. Kuleff, T. Mazza, M. Schöffler, K. Nagaya, M. Yao, Y. Tamenori, N. Saito & K. Ueda | Interatomic Coulombic decay following Ne 1s Auger decay in NeAr | 2011 | Phys. Rev. A 83, 053415 |
|||
| Abstract: {Using momentum-resolved electron-ion multicoincidence spectroscopy, we have investigated Interatomic Coulombic Decay (ICD) in the heteronuclear NeAr dimer following Ne 1s Auger decay. The measured intensity ratio for the three ICD transitions Ne2+(2s-12p-1 1P)Ar to Ne2+(2p-2 1S)-Ar+(3p-1), Ne2+(2s-12p-1 1P)Ar to Ne2+(2p-2 1D)-Ar+(3p-1), and Ne2+(2s-12p-1 3P)Ar to Ne2+(2p-2 3P)-Ar+(3p-1) reasonably agree with predictions. The kinetic energy release distribution for the fragmentation to Ne2+(2p-2 1D)-Ar+(3p-1) after the ICD transition from singlet Ne2+(2s-12p-1 1P)Ar state, which is a mirror image of the kinetic energy distribution of the emitted ICD electrons, suggests that the corresponding ICD rate is roughly twice lower than predicted by ab-initio calculations.} | ||||||
BibTeX:
@article{Ouchi11_1,
author = {Ouchi, T. and Sakai, K. and Fukuzawa, H. and Higuchi, I. and Demekhin, Ph. V. and Chiang, Y.-C. and Stoychev, S. D. and Kuleff, A. I. and Mazza, T. and Schöffler, M. and Nagaya, K. and Yao, M. and Tamenori, Y. and Saito, N. and Ueda, K.},
title = {{Interatomic Coulombic decay following Ne 1s Auger decay in NeAr}},
journal = {Phys. Rev. A},
publisher = {American Physical Society},
year = {2011},
volume = {83},
issue = {5},
pages = {053415},
numpages = {6},
note = {experiment & theory},
doi = {https://doi.org/10.1103/PhysRevA.83.053415}
}
|
||||||
| S.K. Semenov, K. Kreidi, T. Jahnke, Th. Weber, T. Havermeier, R.E. Grisenti, X. Liu, Y. Morisita, L. Ph.H. Schmidt, M. Schöffler, M. Odenweller, N. Neumann, L. Foucar, J. Titze, B. Ulrich, F. Sturm, H.K. Kim, K. Ueda, A. Czasch, O. Jagutzki, N.A. Cherepkov & R. Dörner | Interatomic Coulombic decay of fixed-in-space neon dimers | 2012 | Phys. Rev. A 85, 043421 |
|||
| Abstract: {The detailed theoretical and experimental analysis of the angular distributions of electrons from interatomic Coulombic decay (ICD) of the Ne dimer in the molecular frame is performed. In the initial state the doubly charged dimer ion has one 2s and one 2p vacancies on one atom. After the ICD process the neutral neon atom is ionized and the triply charged molecular ion dissociates into singly and doubly charged atomic ions, Ne2+(2p-2)+ Ne+(2p-1). From the coincident measurement of kinetic energy release (KER) of the ions and the ICD electron the decay channel can be identified unambiguously. The most detailed experimental data have been obtained for the singlet dicationic state Ne2+(2p-2)[1D]. Different KER energies correspond to different internuclear distances at which the ICD process takes place. In experiment the data have been presented for three regions of KER energies, and the corresponding calculations have been performed for three fixed internuclear distances. In calculations we imply that all the electrons in Ne2 to a good approximation are localized. However, we need to retain the molecular character of the dimer wave functions which opens the possibility for the ICD process. To do it, we calculate at first the Hartree-Fock ground state wave functions of the neutral Ne2 dimer using the standard procedure for homonuclear diatomic molecules corresponding to D∞h symmetry group. For the doubly charged ion Ne22+ with two vacancies on one atom the symmetry is lowered to C∞v , and we are looking now for the set of one-electron Hartree-Fock wave functions which are localized either on the left or on the right atom as a linear combination of symmetry adopted wave functions. The theory correctly reproduces the experimental data and predicts the sharp variation of the angular distributions as a function of internuclear distance.} | ||||||
BibTeX:
@article{Semenov12,
author = {Semenov, S. K. and Kreidi, K. and Jahnke, T. and Weber, Th. and Havermeier, T. and Grisenti, R. E. and Liu, X. and Morisita, Y. and Schmidt, L.Ph.H. and Schöffler, M. and Odenweller, M. and Neumann, N. and Foucar, L. and Titze, J. and Ulrich, B. and Sturm, F. and Kim, H.K. and Ueda, K. and Czasch, A. and Jagutzki, O. and Cherepkov, N. A. and Dörner, R.},
title = {{Interatomic Coulombic decay of fixed-in-space neon dimers}},
journal = {Phys. Rev. A},
publisher = {American Physical Society},
year = {2012},
volume = {85},
issue = {4},
pages = {043421},
numpages = {9},
note = {experiment & theory},
doi = {https://doi.org/10.1103/PhysRevA.85.043421}
}
|
||||||
| R.W. Dunford, S.H. Southworth, D. Ray, E.P. Kanter, B. Krässig, L. Young, D.A. Arms, E.M. Dufresne, D.A. Walko, O. Vendrell, S.-K. Son & R. Santra | Evidence for interatomic Coulombic decay in Xe K-shell-vacancy decay of XeF2 | 2012 | Phys. Rev. A 86, 033401 |
|||
| Abstract: {Charge production, charge redistribution, and ion fragmentation are explored in the decay of a Xe K-shell vacancy in XeF2. Coincidence measurements of all ionic fragments in XeF2 provide evidence that an interatomic-Coulombic-decay-like (ICD-like) process plays a role in the cascade decay. The signature of the ICD-like process is an enhancement of the total number of electrons ejected as compared to the case of atomic Xe. The results indicate that the F atoms participate in the decay cascade within the first few femtoseconds after core-hole formation and that fragmentation begins during the decay process.} | ||||||
BibTeX:
@article{Dunford12,
author = {Dunford, R. W. and Southworth, S. H. and Ray, D. and Kanter, E. P. and Krässig, B. and Young, L. and Arms, D. A. and Dufresne, E. M. and Walko, D. A. and Vendrell, O. and Son, S.-K. and Santra, R.},
title = {{Evidence for interatomic Coulombic decay in Xe K-shell-vacancy decay of XeF2}},
journal = {Phys. Rev. A},
publisher = {American Physical Society},
year = {2012},
volume = {86},
issue = {3},
pages = {033401},
numpages = {11},
note = {experiment & theory},
doi = {https://doi.org/10.1103/PhysRevA.86.033401}
}
|
||||||
| F. Trinter, J.B. Williams, M. Weller, M. Waitz, M. Pitzer, J. Voigtsberger, C. Schober, G. Kastirke, C. Müller, C. Goihl, P. Burzynski, F. Wiegandt, R. Wallauer, A. Kalinin, L. Ph.H. Schmidt, M. Schöffler, Y.-C. Chiang, K. Gokhberg, T. Jahnke & R. Dörner | Vibrationally resolved decay width of interatomic Coulombic decay in HeNe | 2013 | Phys. Rev. Lett. 111, 233004 |
|||
| Abstract: {We investigate the ionization of HeNe from below the He 1s3p excitation to the He ionization threshold. We observe HeNe+ ions with an enhancement by more than a factor of 60 when the He side couples resonantly to the radiation field. These ions are an experimental proof of a two-center resonant photoionization mechanism predicted by Najjari et al. [Phys. Rev. Lett. 105, 153002 (2010)]. Furthermore, our data provide electronic and vibrational state resolved decay widths of interatomic Coulombic decay in HeNe dimers. We find that the interatomic Coulombic decay lifetime strongly increases with increasing vibrational state.} | ||||||
BibTeX:
@article{Trinter13b,
author = {Trinter, F. and Williams, J. B. and Weller, M. and Waitz, M. and Pitzer, M. and Voigtsberger, J. and Schober, C. and Kastirke, G. and Müller, C. and Goihl, C. and Burzynski, P. and Wiegandt, F. and Wallauer, R. and Kalinin, A. and Schmidt, L.Ph.H. and Schöffler, M. and Chiang, Y.-C. and Gokhberg, K. and Jahnke, T. and Dörner, R.},
title = {{Vibrationally resolved decay width of interatomic Coulombic decay in HeNe}},
journal = {Phys. Rev. Lett.},
publisher = {American Physical Society},
year = {2013},
volume = {111},
issue = {23},
pages = {233004},
numpages = {5},
note = {experiment & theory},
doi = {https://doi.org/10.1103/PhysRevLett.111.233004}
}
|
||||||
| F. Trinter, J.B. Williams, M. Weller, M. Waitz, M. Pitzer, J. Voigtsberger, C. Schober, G. Kastirke, C. Müller, C. Goihl, P. Burzynski, F. Wiegandt, T. Bauer, R. Wallauer, H. Sann, A. Kalinin, L. Ph.H. Schmidt, M. Schöffler, N. Sisourat & T. Jahnke | Evolution of Interatomic Coulombic Decay in the Time Domain | 2013 | Phys. Rev. Lett. 111, 093401 |
|||
| Abstract: {During the past 15 years a novel decay mechanism of excited atoms has been discovered and investigated. This so-called interatomic Coulombic decay (ICD) involves the chemical environment of the electronically excited atom: the excitation energy is transferred (in many cases over long distances) to a neighbor of the initially excited particle usually ionizing that neighbor. It turned out that ICD is a very common decay route in nature as it occurs across van der Waals and hydrogen bonds. The time evolution of ICD is predicted to be highly complex, as its efficiency strongly depends on the distance of the atoms involved and this distance typically changes during the decay. Here we present the first direct measurement of the temporal evolution of ICD using a novel experimental approach.} | ||||||
BibTeX:
@article{Trinter13a,
author = {Trinter, F. and Williams, J. B. and Weller, M. and Waitz, M. and Pitzer, M. and Voigtsberger, J. and Schober, C. and Kastirke, G. and Müller, C. and Goihl, C. and Burzynski, P. and Wiegandt, F. and Bauer, T. and Wallauer, R. and Sann, H. and Kalinin, A. and Schmidt, L.Ph.H. and Schöffler, M. and Sisourat, N. and Jahnke, T.},
title = {{Evolution of Interatomic Coulombic Decay in the Time Domain}},
journal = {Phys. Rev. Lett.},
publisher = {American Physical Society},
year = {2013},
volume = {111},
issue = {9},
pages = {093401},
numpages = {5},
note = {experiment & theory},
doi = {https://doi.org/10.1103/PhysRevLett.111.093401}
}
|
||||||
| S. Thürmer, I. Unger, P. Slavíček & B. Winter | Relaxation of Electronically Excited Hydrogen Peroxide in Liquid Water: Insights from Auger-Electron Emission | 2013 | J. Phys. Chem. C 117, 22268 |
|||
| Abstract: {Autoionization electron spectroscopy is applied to study non-radiative relaxation processes of hydrogen-peroxide aqueous solution irradiated by soft X-rays. The high-kinetic energy part of the oxygen 1s H2O2(aq) Auger-electron spectrum reveals di-cationic final states with considerably lower energy than for neat liquid water. Assisted by quantum chemical calculations, it is argued that such lower-energy states arise from two fundamentally different relaxation processes. One is (local) Auger decay, yielding H2O22+(aq) species, and here the low final-state energy arises from charge delocalization across the molecular O–O bond. Alternatively, non-local di-cationic states can form, corresponding to a charge-separated complex comprising H2O2 and a neighboring water molecule. Different charge-separation mechanisms, depending on whether or not proton dynamics of the core-level excited- or ionized H2O2 molecule is involved, are discussed. We also present for the first time the partial electron-yield X-ray absorption spectrum of liquid water, which is useful in interpreting the respective spectra from H2O2 in water, especially when identifying solute-specific excitations.} | ||||||
BibTeX:
@article{Thuermer13b,
author = {Thürmer, S. and Unger, I. and Slavíček, P. and Winter, B.},
title = {{Relaxation of Electronically Excited Hydrogen Peroxide in Liquid Water: Insights from Auger-Electron Emission}},
journal = {J. Phys. Chem. C},
publisher = {American Chemical Society},
year = {2013},
volume = {117},
issue = {43},
pages = {22268},
numpages = {8},
note = {experiment & theory},
doi = {https://doi.org/10.1021/jp401569w}
}
|
||||||
| S. Thürmer, M. Ončák, N. Ottosson, R. Seidel, U. Hergenhahn, S.E. Bradforth, P. Slavíček & B. Winter | On the nature and origin of dicationic, charge-separated species formed in liquid water on X-ray irradiation | 2013 | Nat. Chem. 5, 590 |
|||
| Abstract: {To understand the yield and patterns of damage in aqueous condensed matter, including biological systems, it is essential to identify the initial products subsequent to the interaction of high-energy radiation with liquid water. Until now, the observation of several fast reactions induced by energetic particles in water was not possible on their characteristic timescales. Therefore, some of the reaction intermediates involved, particularly those that require nuclear motion, were not considered when describing radiation chemistry. Here, through a combined experimental and theoretical study, we elucidate the ultrafast proton dynamics in the first few femtoseconds after X-ray core-level ionization of liquid water. We show through isotope analysis of the Auger spectra that proton-transfer dynamics occur on the same timescale as electron autoionization. Proton transfer leads to the formation of a Zundel-type intermediate [HO*⋅⋅⋅H⋅⋅⋅H2O]+, which further ionizes to form a so-far unnoticed type of dicationic charge-separated species with high internal energy. We call the process proton-transfer mediated charge separation.} | ||||||
BibTeX:
@article{Thuermer13a,
author = {Thürmer, S. and Ončák, M. and Ottosson, N. and Seidel, R. and Hergenhahn, U. and Bradforth, S. E. and Slavíček, P. and Winter, B.},
title = {{On the nature and origin of dicationic, charge-separated species formed in liquid water on X-ray irradiation}},
journal = {Nat. Chem.},
publisher = {Nature Research},
year = {2013},
volume = {5},
pages = {590},
numpages = {7},
note = {experiment & theory},
doi = {https://doi.org/10.1038/nchem.1680}
}
|
||||||
| K. Schnorr, A. Senftleben, M. Kurka, A. Rudenko, L. Foucar, G. Schmid, A. Broska, T. Pfeifer, K. Meyer, D. Anielski, R. Boll, D. Rolles, M. Kübel, M.F. Kling, Y.H. Jiang, S. Mondal, T. Tachibana, K. Ueda, T. Marchenko, M. Simon, G. Brenner, R. Treusch, S. Scheit, V. Averbukh, J. Ullrich, C.D. Schröter & R. Moshammer | Time-Resolved Measurement of Interatomic Coulombic Decay in Ne2 | 2013 | Phys. Rev. Lett. 111, 093402 |
|||
| Abstract: {The lifetime of interatomic Coulombic decay (ICD) [L. S. Cederbaum et al., Phys. Rev. Lett. 79 4778 (1997)] in Ne2 is determined via an extreme ultraviolet pump-probe experiment at the Free-Electron Laser in Hamburg. The pump pulse creates a 2s inner-shell vacancy in one of the two Ne atoms, whereupon the ionized dimer undergoes ICD resulting in a repulsive Ne+(2p-1) – Ne+(2p-1) state, which is probed with a second pulse, removing a further electron. The yield of coincident Ne+ – Ne2+ pairs is recorded as a function of the pump-probe delay, allowing us to deduce the ICD lifetime of the Ne2+(2s-1) state to be 150±50 fs, in agreement with quantum calculations.} | ||||||
BibTeX:
@article{Schnorr13,
author = {Schnorr, K. and Senftleben, A. and Kurka, M. and Rudenko, A. and Foucar, L. and Schmid, G. and Broska, A. and Pfeifer, T. and Meyer, K. and Anielski, D. and Boll, R. and Rolles, D. and Kübel, M. and Kling, M. F. and Jiang, Y. H. and Mondal, S. and Tachibana, T. and Ueda, K. and Marchenko, T. and Simon, M. and Brenner, G. and Treusch, R. and Scheit, S. and Averbukh, V. and Ullrich, J. and Schröter, C. D. and Moshammer, R.},
title = {{Time-Resolved Measurement of Interatomic Coulombic Decay in Ne2}},
journal = {Phys. Rev. Lett.},
publisher = {American Physical Society},
year = {2013},
volume = {111},
issue = {9},
pages = {093402},
numpages = {5},
note = {experiment & theory},
doi = {https://doi.org/10.1103/PhysRevLett.111.093402}
}
|
||||||
| L.G.M. Pettersson | Radiation chemistry: Radical water | 2013 | Nat. Chem. 5, 553 |
|||
| Abstract: {Radiation of sufficient energy can knock out a tightly bound core-electron from the inner shell of a water molecule, leaving behind a short-lived, highly excited state. Now, through electron spectroscopy and theoretical simulations, these states have been observed to undergo previously unconsidered proton-mediated processes in solution.} | ||||||
BibTeX:
@article{Pettersson13,
author = {Pettersson, L.G.M.},
title = {{Radiation chemistry: Radical water}},
journal = {Nat. Chem.},
publisher = {Nature Research},
year = {2013},
volume = {5},
pages = {553},
numpages = {2},
note = {experiment & theory},
doi = {https://doi.org/10.1038/nchem.1686}
}
|
||||||
| P. Slavíček, B. Winter, L.S. Cederbaum & N.V. Kryzhevoi | Proton-transfer mediated enhancement of non-local electronic relaxation processes in X-ray irradiated liquid water | 2014 | J. Am. Chem. Soc. 136, 18170 |
|||
| Abstract: {We have simulated the oxygen 1s Auger-electron spectra of normal and heavy liquid water using ab initio and quantum dynamical methods. The computed spectra are analyzed and compared to recently reported experimental data. The electronic relaxation in liquid water exposed to ionizing X-ray radiation is shown to be far more diverse and complex than anticipated, and extremely different than for an isolated water molecule. A core-level ionized water molecule in the liquid phase, in addition to a local Auger process, relaxes through non-local energy- and charge-transfer, such as Intermolecular Coulombic Decay (ICD) and Electron Transfer Mediated Decay (ETMD). We evaluate the relative efficiencies for these three classes of relaxation processes. The quantitative estimates for the relative efficiencies of different electronic decay modes help determining yields of various reactive species produced by ionizing X-rays. The ETMD processes which are considered here for the first time in the core-level regime are found to have a surprisingly high efficiency. Importantly, we find that all non-local electronic relaxation processes are significantly enhanced by ultrafast proton transfer between the core-ionized water and neighboring molecules.} | ||||||
BibTeX:
@article{Slavicek14,
author = {Slavíček, P. and Winter, B. and Cederbaum, L. S. and Kryzhevoi, N. V.},
title = {{Proton-transfer mediated enhancement of non-local electronic relaxation processes in X-ray irradiated liquid water}},
journal = {J. Am. Chem. Soc.},
publisher = {American Chemical Society},
year = {2014},
volume = {136},
issue = {52},
pages = {18170},
numpages = {7},
note = {experiment & theory},
doi = {https://doi.org/10.1021/ja5117588}
}
|
||||||
| E. Fasshauer, M. Förstel, S. Pallmann, M. Pernpointner & U. Hergenhahn | Using ICD for structural analysis of clusters: a case study on NeAr clusters | 2014 | New J. Phys. 16, 103026 |
|||
| Abstract: {We present a method to utilize interatomic Coulombic decay (ICD) to retrieve information about the mean geometric structures of heteronuclear clusters. It is based on observation and modelling of competing ICD channels, which involve the same initial vacancy, but energetically different final states with vacancies in different components of the cluster. Using binary rare gas clusters of Ne and Ar as an example, we measure the relative intensity of ICD into (Ne+)2 and Ne+Ar+ final states with spectroscopically well separated ICD peaks. We compare in detail the experimental ratios of the Ne-Ne and Ne-Ar ICD contributions and their positions and widths to values calculated for a diverse set of possible structures. We conclude that NeAr clusters exhibit a core-shell structure with an argon core surrounded by complete neon shells and, possibly, further an incomplete shell of neon atoms for the experimental conditions investigated. Our analysis allows one to differentiate between clusters of similar size and stochiometric Ar content, but different internal structure. We find evidence for ICD of Ne 2s-1, producing Ar+ vacancies in the second coordination shell of the initial site.} | ||||||
BibTeX:
@article{Fasshauer14,
author = {Fasshauer, E. and Förstel, M. and Pallmann, S. and Pernpointner, M. and Hergenhahn, U.},
title = {{Using ICD for structural analysis of clusters: a case study on NeAr clusters}},
journal = {New J. Phys.},
publisher = {IOP},
year = {2014},
volume = {16},
pages = {103026},
numpages = {32},
note = {experiment & theory},
doi = {https://doi.org/10.1088/1367-2630/16/10/103026}
}
|
||||||
| P. Burzynski, F. Trinter, J.B. Williams, M. Weller, M. Waitz, M. Pitzer, J. Voigtsberger, C. Schober, G. Kastirke, C. Müller, C. Goihl, F. Wiegandt, R. Wallauer, A. Kalinin, L. Ph.H. Schmidt, M. Schöffler, G. Schiwietz, N. Sisourat, T. Jahnke & R. Dörner | Interatomic-Coulombic-decay-induced recapture of photoelectrons in helium dimers | 2014 | Phys. Rev. A 90, 022515 |
|||
| Abstract: {We investigate the onset of photoionization shake-up-induced interatomic Coulombic decay (ICD) in He2 at the He+* (n=2) threshold by detecting two He+ ions in coincidence. We find this threshold to be shifted towards higher energies compared to the same threshold in the monomer. The shifted onset of ion pairs created by ICD is attributed to a recapture of the threshold photoelectron after the emission of the faster ICD electron.} | ||||||
BibTeX:
@article{Burzynski14,
author = {Burzynski, P. and Trinter, F. and Williams, J. B. and Weller, M. and Waitz, M. and Pitzer, M. and Voigtsberger, J. and Schober, C. and Kastirke, G. and Müller, C. and Goihl, C. and Wiegandt, F. and Wallauer, R. and Kalinin, A. and Schmidt, L. Ph. H. and Schöffler, M. and Schiwietz, G. and Sisourat, N. and Jahnke, T. and Dörner, R.},
title = {{Interatomic-Coulombic-decay-induced recapture of photoelectrons in helium dimers}},
journal = {Phys. Rev. A},
publisher = {American Physical Society},
year = {2014},
volume = {90},
issue = {2},
pages = {022515},
numpages = {5},
note = {experiment & theory},
doi = {https://doi.org/10.1103/PhysRevA.90.022515}
}
|
||||||
| I. Unger, D. Hollas, R. Seidel, S. Thürmer, E.F. Aziz, P. Slavíček & B. Winter | Control of X-ray Induced Electron and Nuclear Dynamics in Ammonia and Glycine Aqueous Solution via Hydrogen Bonding | 2015 | J. Phys. Chem. B 119, 10750 |
|||
| Abstract: {Recently, a new family of autoionization processes has been identified in aqueous phases. The processes are initiated by core-electron ionization of a solute molecule and involve proton transfer along the solute-solvent hydrogen bond. As a result, short-lived singly charged cations form with structures sharing a proton between solute and solvent molecules. These molecular transients decay by autoionization, which creates reactive dicationic species with the positive charges delocalized over the entire molecular entity. Here, we investigate the ultrafast electron and nuclear dynamics following the core ionization of hydrated ammonia and glycine. Both molecules serve as models for exploring the possible role of the nonlocal relaxation processes in the chemical reactivity at the interface between, for instance, a protein surface and aqueous solution. The nature of the postionization dynamical processes is revealed by high-accuracy Auger-electron spectroscopy measurements on liquid microjets in vacuum. The proton-transfer-mediated processes are identified by electron signals in the high-energy tail of the Auger spectra with no analogue in the Auger spectra of the corresponding gas-phase molecule. This high-energy tail is suppressed for deuterated molecules. Such an isotope effect is found to be smaller for aqueous ammonia as compared to the hydrated H2O molecule, wherein hydrogen bonds are strong. An even weaker hydrogen bonding for the hydrated amino groups in glycine results in a negligibly small proton transfer. The dynamical processes and species formed upon the nitrogen-1s core-level ionization are interpreted using methods of quantum chemistry and molecular dynamics. With the assistance of such calculations, we discuss the conditions for the proton-transfer-mediated relaxation processes to occur. We also consider the solvent librational dynamics as an alternative intermolecular ultrafast relaxation pathway. In addition, we provide experimental evidence for the umbrella-type motion in aqueous ammonia upon core ionization. This intramolecular channel proceeds in parallel with intermolecular relaxation processes in the solution.} | ||||||
BibTeX:
@article{Unger15,
author = {Unger, I. and Hollas, D. and Seidel, R. and Thürmer, S. and Aziz, E. F. and Slavíček, P. and Winter, B.},
title = {{Control of X-ray Induced Electron and Nuclear Dynamics in Ammonia and Glycine Aqueous Solution via Hydrogen Bonding}},
journal = {J. Phys. Chem. B},
publisher = {American Chemical Society},
year = {2015},
volume = {119},
issue = {33},
pages = {10750},
numpages = {10},
note = {experiment & theory},
doi = {https://doi.org/10.1021/acs.jpcb.5b07283}
}
|
||||||
| B. Schütte, M. Arbeiter, T. Fennel, G. Jabbari, A.I. Kuleff, M.J.J. Vrakking & A. Rouzée | Observation of correlated electronic decay in expanding clusters triggered by near-infrared fields | 2015 | Nat. Commun. 6, 8596 |
|||
| Abstract: {When an excited atom is embedded into an environment, novel relaxation pathways can emerge that are absent for isolated atoms. A well-known example is interatomic Coulombic decay, where an excited atom relaxes by transferring its excess energy to another atom in the environment, leading to its ionization. Such processes have been observed in clusters ionized by extreme-ultraviolet and X-ray lasers. Here, we report on a correlated electronic decay process that occurs following nanoplasma formation and Rydberg atom generation in the ionization of clusters by intense, non-resonant infrared laser fields. Relaxation of the Rydberg states and transfer of the available electronic energy to adjacent electrons in Rydberg states or quasifree electrons in the expanding nanoplasma leaves a distinct signature in the electron kinetic energy spectrum. These so far unobserved electron-correlation-driven energy transfer processes may play a significant role in the response of any nano-scale system to intense laser light.} | ||||||
BibTeX:
@article{Schuette15a,
author = {Schütte, B. and Arbeiter, M. and Fennel, T. and Jabbari, G. and Kuleff, A. I. and Vrakking, M.J.J. and Rouzée, A.},
title = {{Observation of correlated electronic decay in expanding clusters triggered by near-infrared fields}},
journal = {Nat. Commun.},
publisher = {Nature Research},
year = {2015},
volume = {6},
pages = {8596},
numpages = {7},
note = {experiment & theory},
doi = {https://doi.org/10.1038/ncomms9596}
}
|
||||||
| B. Schütte, M. Arbeiter, T. Fennel, G. Jabbari, A.I. Kuleff, M.J.J. Vrakking & A. Rouzée | Correlated electronic decay following intense near-infrared ionization of clusters | 2015 | J. Phys.: Conf. Ser. 635, 012025 |
|||
| Abstract: {We report on a novel correlated electronic decay process following extensive Rydberg atom formation in clusters ionized by intense near-infrared fields. A peak close to the atomic ionization potential is found in the electron kinetic energy spectrum. This new contribution is attributed to an energy transfer between two electrons, where one electron decays from a Rydberg state to the ground state and transfers its excess energy to a weakly bound cluster electron in the environment that can escape from the cluster. The process is a result of nanoplasma formation and is therefore expected to be important, whenever intense laser pulses interact with nanometer-sized particles.} | ||||||
BibTeX:
@proceedings{Schuette15b,
author = {Schütte, B. and Arbeiter, M. and Fennel, T. and Jabbari, G. and Kuleff, A. I. and Vrakking, M.J.J. and Rouzée, A.},
title = {{Correlated electronic decay following intense near-infrared ionization of clusters}},
journal = {J. Phys.: Conf. Ser.},
series= {XXIX International Conference on Photonic, Electronic, and Atomic Collisions (ICPEAC2015)},
publisher = {IOP},
year = {2015},
volume = {635},
pages = {012025},
numpages = {6},
note = {experiment & theory},
doi = {https://doi.org/10.1088/1742-6596/635/1/012025}
}
|
||||||
| K. Schnorr, A. Senftleben, G. Schmid, S. Augustin, M. Kurka, A. Rudenko, L. Foucar, A. Broska, K. Meyer, D. Anielski, D. Anielski, R. Boll, D. Rolles, M. Kübel, M.F. Kling, Y.H. Jiang, S. Mondal, T. Tachibana, K. Ueda, T. Marchenko, M. Simon, G. Brenner, R. Treusch, S. Scheit, V. Averbukh, J. Ullrich, T. Pfeifer, C.D. Schröter & R. Moshammer | Time-resolved study of ICD in Ne dimers using FEL radiation | 2015 | J. Electron Spectrosc. Relat. Phenom. 204, 245 |
|||
| Abstract: {Interatomic Coulombic Decay (ICD) is a relaxation phenomenon, which takes place in weakly bound atomic and molecular systems, typically within a few to hundreds of femtoseconds depending on the system and the particular decay mechanism. The creation of ICD-active states requires the production of highly excited systems, usually populated by innershell ionization or excitation. To this end, XUV and X-ray radiation from synchrotrons was conventionally applied for the majority of experiments due to the desired state-selective ionization of certain sub-shells. The advent of Free-Electron Lasers (FELs) has enabled an entirely new class of experiments, which finally allow to trace ICD directly in the time domain due to the femtosecond pulse duration. Within this paper, the first time-resolved ICD measurement using an XUV-pump-XUV-probe scheme will be discussed in detail. The experiment was performed on neon dimers and ICD was triggered by removing a 2s electron from one of the neon atoms using a 58 eV pulse from the FEL in Hamburg (FLASH). The onset of ICD was probed with a delayed copy of the trigger pulse that further ionized one of the two Ne+ ions emerging after ICD. Thus, the delay-dependent yield of coincident Ne+ + Ne2+ ion pairs contains the lifetime of the 2s-innershell vacancy decaying via ICD. The result of 150 fs ± 50 fs is in good agreement with theory but only for those calculations that explicitly take nuclear motion into account.} | ||||||
BibTeX:
@article{Schnorr15,
author = {Schnorr, K. and Senftleben, A. and Schmid, G. and Augustin, S. and Kurka, M. and Rudenko, A. and Foucar, L. and Broska, A. and Meyer, K. and Anielski, D. and Anielski, D. and Boll, R. and Rolles, D. and Kübel, M. and Kling, M. F. and Jiang, Y. H. and Mondal, S. and Tachibana, T. and Ueda, K. and Marchenko, T. and Simon, M. and Brenner, G. and Treusch, R. and Scheit, S. and Averbukh, V. and Ullrich, J. and Pfeifer, T. and Schröter, C. D. and Moshammer, R.},
title = {{Time-resolved study of ICD in Ne dimers using FEL radiation}},
journal = {J. Electron Spectrosc. Relat. Phenom.},
publisher = {Elsevier},
year = {2015},
volume = {204},
pages = {245},
numpages = {12},
note = {experiment & theory},
doi = {https://doi.org/10.1016/j.elspec.2015.07.009}
}
|
||||||
| T. Jahnke | Interatomic and intermolecular Coulombic decay: the coming of age story | 2015 | J. Phys. B: At. Mol. Opt. Phys. 48, 082001 |
|||
| Abstract: {In pioneering work by Cederbaum et al an excitation mechanism was proposed that occurs only in loosely bound matter (Cederbaum et al 1997 Phys. Rev. Lett. 79 4778): it turned out, that (in particular) in cases where a local Auger decay is energetically forbidden, an excited atom or molecule is able to decay in a scheme which was termed 'interatomic Coulombic decay' (or 'intermolecular Coulombic decay') (ICD). As ICD occurs, the excitation energy is released by transferring it to an atomic or molecular neighbor of the initially excited particle. As a consequence the neighboring atom or molecule is ionized as it receives the energy. A few years later the existence of ICD was confirmed experimentally (Marburger et al 2003 Phys. Rev. Lett. 90 203401; Jahnke et al 2004 Phys. Rev. Lett. 93 163401; Öhrwall et al 2004 Phys. Rev. Lett. 93 173401) by different techniques. Since this time it has been found that ICD is not (as initially suspected) an exotic feature of van der Waals or hydrogen bonded systems, but that ICD is a very general and common feature occurring after a manifold of excitation schemes and in numerous weakly bound systems, as revealed by more than 200 publications. It was even demonstrated, that ICD can become more efficient than a local Auger decay in some system. This review will concentrate on recent experimental investigations on ICD. It will briefly introduce the phenomenon and give a short summary of the 'early years' of ICD (a detailed view on this episode of investigations can be found in the review article by U Hergenhahn with the same title (Hergenhahn 2011 J. Electron Spectrosc. Relat. Phenom. 184 78)). More recent articles will be presented that investigate the relevance of ICD in biological systems and possible radiation damage of such systems due to ICD. The occurrence of ICD and ICD-like processes after different excitation schemes and in different systems is covered in the middle section: in that context the helium dimer (He2) is a particularly interesting (and exotic) system in which ICD was detected. It was employed in several publications to elucidate the strong impact of nuclear motion on ICD and its longrange-character. The review will present these findings and their initial theoretical predictions and give insight into most recent time-resolved measurements of ICD.} | ||||||
BibTeX:
@article{Jahnke15,
author = {Jahnke, T.},
title = {{Interatomic and intermolecular Coulombic decay: the coming of age story}},
journal = {J. Phys. B: At. Mol. Opt. Phys.},
publisher = {IOP},
year = {2015},
volume = {48},
issue = {8},
pages = {082001},
numpages = {20},
note = {experiment & theory},
doi = {https://doi.org/10.1088/0953-4075/48/8/082001}
}
|
||||||
| A. Dubrouil, M. Reduzzi, M. Devetta, C. Feng, J. Hummert, P. Finetti, O. Plekan, C. Grazioli, M. Di Fraia, V. Lyamayev, A. La Forge, R. Katzy, F. Stienkemeier, Y. Ovcharenko, M. Coreno, N. Berrah, K. Motomura, S. Mondal, K. Ueda, K.C. Prince, C. Callegari, A.I. Kuleff, Ph.V. Demekhin & G. Sansone | Two-photon resonant excitation of interatomic coulombic decay in neon dimers | 2015 | J. Phys. B: At. Mol. Opt. Phys. 48, 204005 |
|||
| Abstract: {The recent availability of intense and ultrashort extreme ultraviolet sources opens up the possibility of investigating ultrafast electronic relaxation processes in matter in an unprecedented regime. In this work we report on the observation of two-photon excitation of interatomic Coulombic decay (ICD) in neon dimers using the tunable intense pulses delivered by the free electron laser FERMI. The unique characteristics of FERMI (narrow bandwidth, spectral stability, and tunability) allow one to resonantly excite specific ionization pathways and to observe a clear signature of the ICD mechanism in the ratio of the ion yield created by Coulomb explosion. The present experimental results are explained by ab initio electronic structure and nuclear dynamics calculations.} | ||||||
BibTeX:
@article{Dubrouil15,
author = {Dubrouil, A. and Reduzzi, M. and Devetta, M. and Feng, C. and Hummert, J. and Finetti, P. and Plekan, O. and Grazioli, C. and Di Fraia, M. and Lyamayev, V. and La Forge, A. and Katzy, R. and Stienkemeier, F. and Ovcharenko, Y. and Coreno, M. and Berrah, N. and Motomura, K. and Mondal, S. and Ueda, K. and Prince, K. C. and Callegari, C. and Kuleff, A. I. and Demekhin, Ph. V. and Sansone, G.},
title = {{Two-photon resonant excitation of interatomic coulombic decay in neon dimers}},
journal = {J. Phys. B: At. Mol. Opt. Phys.},
publisher = {IOP},
year = {2015},
volume = {48},
issue = {20},
pages = {204005},
numpages = {8},
note = {experiment & theory},
doi = {https://doi.org/10.1088/0953-4075/48/20/204005}
}
|
||||||
| P. Slavíček, N.V. Kryzhevoi, E.F. Aziz & B. Winter | Relaxation Processes in Aqueous Systems upon X-ray Ionization: Entanglement of Electronic and Nuclear Dynamics | 2016 | J. Phys. Chem. Lett. 7, 234 |
|||
| Abstract: {The knowledge of primary processes following the interaction of high-energy radiation with molecules in liquid phase is rather limited. In the present perspective, we report on a newly discovered type of relaxation process involving simultaneous autoionization and proton transfer between adjacent molecules, so called proton transfer mediated charge separation (PTM-CS) process. Within PTM-CS, transients with a half-transferred proton are formed within a few femtoseconds after the core-level ionization event. Subsequent non-radiative decay of the highly non-equilibrium transients leads to a series of reactive species which have not been considered in any high-energy radiation process in water. Non-local electronic decay processes are surprisingly accelerated upon proton dynamics. Such strong coupling of electronic and nuclear dynamics is a general phenomenon for hydrogen-bonded systems, however, its probability correlates strongly with hydration geometry. We suggest that the newly observed processes will impact future high-energy radiation-chemistry-relevant modeling, and we envision application of autoionization spectroscopy for identification of solution structure details.} | ||||||
BibTeX:
@article{Slavicek16,
author = {Slavíček, P. and Kryzhevoi, N. V. and Aziz, E. F. and Winter, B.},
title = {{Relaxation Processes in Aqueous Systems upon X-ray Ionization: Entanglement of Electronic and Nuclear Dynamics}},
journal = {J. Phys. Chem. Lett.},
publisher = {American Chemical Society},
year = {2016},
volume = {7},
pages = {234},
numpages = {10},
note = {experiment & theory},
doi = {https://doi.org/10.1021/acs.jpclett.5b02665}
}
|
||||||
| K. Nagaya, D. Iablonskyi, N.V. Golubev, K. Matsunami, H. Fukuzawa, K. Motomura, T. Nishiyama, T. Sakai, T. Tachibana, S. Mondal, S. Wada, K.C. Prince, C. Callegari, C. Miron, N. Saito, M. Yabashi, Ph.V. Demekhin, L.S. Cederbaum, A.I. Kuleff, M. Yao & K. Ueda | Interatomic Coulombic decay cascades in multiply excited neon clusters | 2016 | Nat. Commun. 7, 13477 |
|||
| Abstract: {In high-intensity laser light, matter can be ionized by direct multiphoton absorption even at photon energies below the ionization threshold. However on tuning the laser to the lowest resonant transition, the system becomes multiply excited, and more efficient, indirect ionization pathways become operative. These mechanisms are known as interatomic Coulombic decay (ICD), where one of the species de-excites to its ground state, transferring its energy to ionize another excited species. Here we show that on tuning to a higher resonant transition, a previously unknown type of interatomic Coulombic decay, intra-Rydberg ICD occurs. In it, de-excitation of an atom to a close-lying Rydberg state leads to electron emission from another neighbouring Rydberg atom. Moreover, systems multiply excited to higher Rydberg states will decay by a cascade of such processes, producing even more ions. The intra-Rydberg ICD and cascades are expected to be ubiquitous in weakly-bound systems exposed to high-intensity resonant radiation.} | ||||||
BibTeX:
@article{Nagaya16,
author = {Nagaya, K. and Iablonskyi, D. and Golubev, N. V. and Matsunami, K. and Fukuzawa, H. and Motomura, K. and Nishiyama, T. and Sakai, T. and Tachibana, T. and Mondal, S. and Wada, S. and Prince, K. C. and Callegari, C. and Miron, C. and Saito, N. and Yabashi, M. and Demekhin, Ph. V. and Cederbaum, L. S. and Kuleff, A. I. and Yao, M. and Ueda, K.},
title = {{Interatomic Coulombic decay cascades in multiply excited neon clusters}},
journal = {Nat. Commun.},
publisher = {Nature Research},
year = {2016},
volume = {7},
pages = {13477},
numpages = {6},
note = {experiment & theory},
doi = {https://doi.org/10.1038/ncomms13477}
}
|
||||||
| M. Magrakvelidze, R. De, M.H. Javani, M.E. Madjet, S.T. Manson & H.S. Chakraborty | Coherence of Auger and inter-Coulombic decay processes in the photoionization of Ar@C60 versus Kr@C60 | 2016 | Eur. Phys. J. D 70, 96 |
|||
| Abstract: {For the asymmetric spherical dimer of an endohedrally confined atom and a host fullerene, an innershell vacancy of either system can decay through the continuum of an outer electron hybridized between the systems. Such decays, viewed as coherent superpositions of the single-center Auger and two-center inter-Coulombic (ICD) amplitudes, are found to govern leading decay mechanisms in noble-gas endofullerenes, and are likely omnipresent in this class of nanomolecules. A comparison between resulting autoionizing resonances calculated in the photoionization of Ar@C60 and Kr@C60 exhibits details of the underlying processes.} | ||||||
BibTeX:
@article{Magrakvelidze16,
author = {Magrakvelidze, M. and De, R. and Javani, M. H. and Madjet, M. E. and Manson, S. T. and Chakraborty, H. S.},
title = {{Coherence of Auger and inter-Coulombic decay processes in the photoionization of Ar@C60 versus Kr@C60}},
journal = {Eur. Phys. J. D},
publisher = {Springer},
year = {2016},
volume = {70},
issue = {4},
pages = {96},
numpages = {7},
note = {experiment & theory},
doi = {https://doi.org/10.1140/epjd/e2016-60703-y}
}
|
||||||
| A.C. LaForge, V. Stumpf, K. Gokhberg, J. von Vangerow, F. Stienkemeier, N.V. Kryzhevoi, P. O'Keeffe, A. Ciavardini, S.R. Krishnan, M. Coreno, K.C. Prince, R. Richter, R. Moshammer, T. Pfeifer, L.S. Cederbaum & M. Mudrich | Enhanced Ionization of Embedded Clusters by Electron-Transfer-Mediated Decay in Helium Nanodroplets | 2016 | Phys. Rev. Lett. 116, 203001 |
|||
| Abstract: {We report the observation of electron-transfer-mediated decay (ETMD) involving magnesium (Mg) clusters embedded in helium (He) nanodroplets. ETMD is initiated by the ionization of He followed by removal of two electrons from the Mg clusters of which one is transferred to the He ion while the other electron is emitted into the continuum. The process is shown to be the dominant ionization mechanism for embedded clusters for photon energies above the ionization potential of He. For Mg clusters larger than five atoms we observe stable doubly ionized clusters. Thus, ETMD provides an efficient pathway to the formation of doubly ionized cold species in doped nanodroplets.} | ||||||
BibTeX:
@article{LaForge16,
author = {LaForge, A. C. and Stumpf, V. and Gokhberg, K. and von Vangerow, J. and Stienkemeier, F. and Kryzhevoi, N. V. and O'Keeffe, P. and Ciavardini, A. and Krishnan, S. R. and Coreno, M. and Prince, K. C. and Richter, R. and Moshammer, R. and Pfeifer, T. and Cederbaum, L. S. and Mudrich, M.},
title = {{Enhanced Ionization of Embedded Clusters by Electron-Transfer-Mediated Decay in Helium Nanodroplets}},
journal = {Phys. Rev. Lett.},
publisher = {American Physical Society},
year = {2016},
volume = {116},
issue = {20},
pages = {203001},
numpages = {5},
note = {experiment & theory},
doi = {https://doi.org/10.1103/PhysRevLett.116.203001}
}
|
||||||
| P. Kolorenč, V. Averbukh, R. Feifel & J. Eland | Collective relaxation processes in atoms, molecules and clusters | 2016 | J. Phys. B: At. Mol. Opt. Phys. 49, 082001 |
|||
| Abstract: {Electron correlation is an essential driver of a variety of relaxation processes in excited atomic and molecular systems. These are phenomena which often lead to autoionization typically involving two-electron transitions, such as the well-known Auger effect. However, electron correlation can give rise also to higher-order processes characterized by multi-electron transitions. Basic examples include simultaneous two-electron emission upon recombination of an inner-shell vacancy (double Auger decay) or collective decay of two holes with emission of a single electron. First reports of this class of processes date back to the 1960s, but their investigation intensified only recently with the advent of free-electron lasers. High fluxes of high-energy photons induce multiple excitation or ionization of a system on the femtosecond timescale and under such conditions the importance of multi-electron processes increases significantly. We present an overview of experimental and theoretical works on selected multi-electron relaxation phenomena in systems of different complexity, going from double Auger decay in atoms and small molecules to collective interatomic autoionization processes in nanoscale samples.} | ||||||
BibTeX:
@article{Kolorenc16,
author = {Kolorenč, P. and Averbukh, V. and Feifel, R. and Eland, J.},
title = {{Collective relaxation processes in atoms, molecules and clusters}},
journal = {J. Phys. B: At. Mol. Opt. Phys.},
publisher = {IOP},
year = {2016},
volume = {49},
issue = {8},
pages = {082001},
numpages = {18},
note = {experiment & theory},
doi = {https://doi.org/10.1088/0953-4075/49/8/082001}
}
|
||||||
| M. Förstel, M. Mucke, T. Arion, T. Lischke, M. Pernpointner, U. Hergenhahn & E. Fasshauer | Long-Range Interatomic Coulombic Decay in ArXe Clusters: Experiment and Theory | 2016 | J. Phys. Chem. C 120, 22957 |
|||
| Abstract: {We report autoionization channels of Ar inner valence ionized states in mixed ArXe clusters and compare our experimental data obtained by electron-electron coincidence spectroscopy to our theoretical simulations for representative cluster structures. The combined experimental and theoretical data show that the autoionization of Ar 3s-1 in ArXe is dominated by interatomic coulombic decay (ICD) to Xe atoms in the second and higher coordination shells of the originally excited atom. Clusters with a range of sizes, compositions, and structures were probed. The Xe content in the clusters was varied between 10% and 53%. Besides ICD, also electron transfer mediated decay (ETMD(3)) was found important in many of the calculated spectra, although it is seen with less intensity in the experimental spectra. From the calculations, we identify structural motifs in which the ETMD rate is minimized vs the ICD rate and suggest that these are preferentially realized in our experiment, in which clusters are formed by supersonic expansion of an Ar-Xe mixture. Suggested cluster structures either feature a clear segregation between Ar and Xe fractions, e.g., Xe core-Ar shell systems, or contain a few Xe atoms singled out at surface sites on an Ar cluster. These structures differ significantly from the majority of calculated minimum energy structures for ArXe systems of 38 atoms, which might show that the latter, annealed structures are not realized in our experiment. We show experimentally that the relaxation of Ar inner valence states by ICD and ETMD together has an efficiency of unity, within the experimental accuracy, for all clusters probed, except those with the lowest Xe content. The outer valence photoelectron spectra of ArXe are discussed also.} | ||||||
BibTeX:
@article{Foerstel16,
author = {Förstel, M. and Mucke, M. and Arion, T. and Lischke, T. and Pernpointner, M. and Hergenhahn, U. and Fasshauer, E},
title = {{Long-Range Interatomic Coulombic Decay in ArXe Clusters: Experiment and Theory}},
journal = {J. Phys. Chem. C},
publisher = {American Chemical Society},
year = {2016},
volume = {120},
issue = {40},
pages = {22957},
numpages = {15},
note = {experiment & theory},
doi = {https://doi.org/10.1021/acs.jpcc.6b06665}
}
|
||||||
| R. De, M. Magrakvelidze, M.E. Madjet, S.T. Manson & H.S. Chakraborty | First prediction of inter-Coulombic decay of C60 inner vacancies through the continuum of confined atoms | 2016 | J. Phys. B: At. Mol. Opt. Phys. 49, 11LT01 |
|||
| Abstract: {Considering the photoionization of Ar@C60 and Kr@C60 endofullerenes, the decay of C60 innershell excitations through the outershell continuum of the confined atom via the inter-Coulombic decay (ICD) pathway is detailed. Excitations to atom-C60 hybrid states, when these states exist, can induce coherence between ICD and electron-transfer mediated decay (ETMD). This should be the dominant above-threshold decay process for a variety of confined systems, and the strength of these resonances is such that they should be amenable for study by photoelectron spectroscopy.} | ||||||
BibTeX:
@article{De16,
author = {De, R. and Magrakvelidze, M. and Madjet, M. E. and Manson, S. T. and Chakraborty, H. S.},
title = {{First prediction of inter-Coulombic decay of C60 inner vacancies through the continuum of confined atoms}},
journal = {J. Phys. B: At. Mol. Opt. Phys.},
publisher = {IOP},
year = {2016},
volume = {49},
issue = {11},
pages = {11LT01},
numpages = {5},
note = {experiment & theory},
doi = {https://doi.org/10.1088/0953-4075/49/11/11LT01}
}
|
||||||
| D. You, H. Fukuzawa, Y. Sakakibara, T. Takanashi, Y. Ito, G.G. Maliyar, K. Motomura, K. Nagaya, T. Nishiyama, K. Asa, Y. Sato, N. Saito, M. Oura, M. Schöffler, G. Kastirke, U. Hergenhahn, V. Stumpf, K. Gokhberg, A.I. Kuleff, L.S. Cederbaum & K. Ueda | Charge transfer to ground-state ions produces free electrons | 2017 | Nat. Commun. 8, 14277 |
|||
| Abstract: {Inner-shell ionization of an isolated atom typically leads to Auger decay. In an environment, for example, a liquid or a van der Waals bonded system, this process will be modified, and becomes part of a complex cascade of relaxation steps. Understanding these steps is important, as they determine the production of slow electrons and singly charged radicals, the most abundant products in radiation chemistry. In this communication, we present experimental evidence for a so-far unobserved, but potentially very important step in such relaxation cascades: Multiply charged ionic states after Auger decay may partially be neutralized by electron transfer, simultaneously evoking the creation of a low-energy free electron (electron transfer-mediated decay). This process is effective even after Auger decay into the dicationic ground state. In our experiment, we observe the decay of Ne2+ produced after Ne 1s photoionization in Ne-Kr mixed clusters.} | ||||||
BibTeX:
@article{You17,
author = {You, D. and Fukuzawa, H. and Sakakibara, Y. and Takanashi, T. and Ito, Y. and Maliyar, G. G. and Motomura, K. and Nagaya, K. and Nishiyama, T. and Asa, K. and Sato, Y. and Saito, N. and Oura, M. and Schöffler, M. and Kastirke, G. and Hergenhahn, U. and Stumpf, V. and Gokhberg, K. and Kuleff, A. I. and Cederbaum, L. S. and Ueda, K.},
title = {{Charge transfer to ground-state ions produces free electrons}},
journal = {Nat. Commun.},
publisher = {Nature Research},
year = {2017},
volume = {8},
pages = {14277},
numpages = {6},
note = {experiment & theory},
doi = {https://doi.org/10.1038/ncomms14277}
}
|
||||||
| I. Unger, R. Seidel, S. Thürmer, M.N. Pohl, E.F. Aziz, L.S. Cederbaum, E. Muchová, P. Slavíček, B. Winter & N.V. Kryzhevoi | Observation of electron-transfer-mediated decay in aqueous solution | 2017 | Nat. Chem. 9, 708 |
|||
| Abstract: {Photoionization is at the heart of X-ray photoelectron spectroscopy (XPS), which gives access to important information on a sample's local chemical environment. Local and non-local electronic decay after photoionization-in which the refilling of core holes results in electron emission from either the initially ionized species or a neighbour, respectively-have been well studied. However, electron-transfer-mediated decay (ETMD), which involves the refilling of a core hole by an electron from a neighbouring species, has not yet been observed in condensed phase. Here we report the experimental observation of ETMD in an aqueous LiCl solution by detecting characteristic secondary low-energy electrons using liquid-microjet soft XPS. Experimental results are interpreted using molecular dynamics and high-level ab initio calculations. We show that both solvent molecules and counterions participate in the ETMD processes, and different ion associations have distinctive spectral fingerprints. Furthermore, ETMD spectra are sensitive to coordination numbers, ion-solvent distances and solvent arrangement.} | ||||||
BibTeX:
@article{Unger17,
author = {Unger, I. and Seidel, R. and Thürmer, S. and Pohl, M. N. and Aziz, E. F. and Cederbaum, L. S. and Muchová, E. and Slavíček, P. and Winter, B. and Kryzhevoi, N. V.},
title = {{Observation of electron-transfer-mediated decay in aqueous solution}},
journal = {Nat. Chem.},
publisher = {Nature Research},
year = {2017},
volume = {9},
pages = {708},
numpages = {7},
note = {experiment & theory},
doi = {https://doi.org/10.1038/nchem.2727}
}
|
||||||
| T. Takanashi, N.V. Golubev, C. Callegari, H. Fukuzawa, K. Motomura, D. Iablonskyi, Y. Kumagai, S. Mondal, T. Tachibana, K. Nagaya, T. Nishiyama, K. Matsunami, P. Johnsson, P. Piseri, G. Sansone, A. Dubrouil, M. Reduzzi, P. Carpeggiani, C. Vozzi, M. Devetta, M. Negro, D. Faccialà, F. Calegari, A. Trabattoni, M.C. Castrovilli, Y. Ovcharenko, M. Mudrich, F. Stienkemeier, M. Coreno, M. Alagia, B. Schütte, N. Berrah, O. Plekan, P. Finetti, C. Spezzani, E. Ferrari, E. Allaria, G. Penco, C. Serpico, G. De Ninno, B. Diviacco, S. Di Mitri, L. Giannessi, G. Jabbari, K.C. Prince, L.S. Cederbaum, Ph.V. Demekhin, A.I. Kuleff & K. Ueda | Time-Resolved Measurement of Interatomic Coulombic Decay Induced by Two-Photon Double Excitation of Ne2 | 2017 | Phys. Rev. Lett. 118, 033202 |
|||
| Abstract: {The hitherto unexplored two-photon doubly excited states [Ne*(2p-13s)]2 were experimentally identified using the seeded, fully coherent, intense extreme ultraviolet free-electron laser FERMI. These states undergo ultrafast interatomic Coulombic decay (ICD), which predominantly produces singly ionized dimers. In order to obtain the rate of ICD, the resulting yield of Ne+2 ions was recorded as a function of delay between the extreme ultraviolet pump and UV probe laser pulses. The extracted lifetimes of the long-lived doubly excited states, 390(-130/+450) fs, and of the short-lived ones, less than 150 fs, are in good agreement with ab initio quantum mechanical calculations.} | ||||||
BibTeX:
@article{Takanashi17,
author = {Takanashi, T. and Golubev, N. V. and Callegari, C. and Fukuzawa, H. and Motomura, K. and Iablonskyi, D. and Kumagai, Y. and Mondal, S. and Tachibana, T. and Nagaya, K. and Nishiyama, T. and Matsunami, K. and Johnsson, P. and Piseri, P. and Sansone, G. and Dubrouil, A. and Reduzzi, M. and Carpeggiani, P. and Vozzi, C. and Devetta, M. and Negro, M. and Faccialà, D. and Calegari, F. and Trabattoni, A. and Castrovilli, M. C. and Ovcharenko, Y. and Mudrich, M. and Stienkemeier, F. and Coreno, M. and Alagia, M. and Schütte, B. and Berrah, N. and Plekan, O. and Finetti, P. and Spezzani, C. and Ferrari, E. and Allaria, E. and Penco, G. and Serpico, C. and De Ninno, G. and Diviacco, B. and Di Mitri, S. and Giannessi, L. and Jabbari, G. and Prince, K. C. and Cederbaum, L. S. and Demekhin, Ph. V. and Kuleff, A. I. and and Ueda, K.},
title = {{Time-Resolved Measurement of Interatomic Coulombic Decay Induced by Two-Photon Double Excitation of Ne2}},
journal = {Phys. Rev. Lett.},
publisher = {American Physical Society},
year = {2017},
volume = {118},
pages = {033202},
numpages = {6},
note = {experiment & theory},
doi = {https://doi.org/10.1103/PhysRevLett.118.033202}
}
|
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| J. Rist, T. Miteva, B. Gaire, H. Sann, T. Trinter, M. Keiling, N. Gehrken, A. Moradmand, B. Berry, M. Zohrabi, M. Kunitski, I. Ben-Itzhak, A. Belkacem, T. Weber, A.L. Landers, M. Schöffler, J.B. Williams, P. Kolorenč, K. Gokhberg, T. Jahnke & R. Dörner | A comprehensive study of Interatomic Coulombic Decay in argon dimers: Extracting R-dependent absolute decay rates from the experiment | 2017 | Chem. Phys. 482, 185 |
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| Abstract: {In this work we present a comprehensive and detailed study of Interatomic Coulombic Decay (ICD) occurring after irradiating argon dimers with XUV-synchrotron radiation. A manifold of different decay channels is observed and the corresponding initial and final states are assigned. Additionally, the effect of nuclear dynamics on the ICD electron spectrum is examined for one specific decay channel. The internuclear distance-dependent width Γ(R) of the decay is obtained from the measured kinetic energy release distribution of the ions employing a classical nuclear dynamics model.} | ||||||
BibTeX:
@article{Rist17,
author = {Rist, J. and Miteva, T. and Gaire, B. and Sann, H. and Trinter, T. and Keiling, M. and Gehrken, N. and Moradmand, A. and Berry, B. and Zohrabi, M. and Kunitski, M. and Ben-Itzhak, I. and Belkacem, A. and Weber, T. and Landers, A. L. and Schöffler, M. and Williams, J. B. and Kolorenč, P. and Gokhberg, K. and Jahnke, T. and Dörner, R.},
title = {{A comprehensive study of Interatomic Coulombic Decay in argon dimers: Extracting R-dependent absolute decay rates from the experiment}},
journal = {Chem. Phys.},
publisher = {Elsevier},
year = {2017},
volume = {482},
pages = {185},
numpages = {7},
note = {experiment & theory},
doi = {https://doi.org/10.1016/j.chemphys.2016.09.024}
}
|
||||||
| X. Ren, T. Miteva, P. Kolorenč, K. Gokhberg, A.I. Kuleff, L.S. Cederbaum & A. Dorn | Observation of fast and slow interatomic Coulombic decay in argon dimers induced by electron-impact ionization | 2017 | Phys. Rev. A 96, 032715 |
|||
| Abstract: {We investigate the interatomic Coulombic decay (ICD) in argon dimers induced by electron-impact ionization (E0=90eV) using a multiparticle coincidence experiment in which the momentum vectors and, consequently, the kinetic energies for electrons and fragment ions are determined. The signature of the ICD process is obtained from a correlation map between ejected electron energy and kinetic energy release (KER) for Ar++Ar+ fragment ions where low-energy ICD electrons can be identified. Furthermore, two types of ICD processes, termed fast and slow interatomic decay, are separated by the ICD initial-state energies and projectile energy losses. The dependence of the energies of emitted low-energy ICD electrons on the initial-state energy is studied. ICD electron energy spectra and KER spectra are obtained separately for fast and slow decay processes where the KER spectra for the slow decay channel are strongly influenced by nuclear motion. The KER and ICD electron energy spectra are well reproduced by ab initio calculations.} | ||||||
BibTeX:
@article{Ren17,
author = {Ren, X. and Miteva, T. and Kolorenč, P. and Gokhberg, K. and Kuleff, A. I. and Cederbaum, L. S. and Dorn, A.},
title = {{Observation of fast and slow interatomic Coulombic decay in argon dimers induced by electron-impact ionization}},
journal = {Phys. Rev. A},
publisher = {American Physical Society},
year = {2017},
volume = {96},
pages = {032715},
numpages = {6},
note = {experiment & theory},
doi = {https://doi.org/10.1103/PhysRevA.96.032715}
}
|
||||||
| T. Ouchi, V. Stumpf, T. Miteva, H. Fukuzawa, K. Sakai, X.-J. Liu, T. Mazza, M. Schöffler, H. Iwayama, K. Nagaya, Y. Tamenori, N. Saito, A.I. Kuleff, K. Gokhberg & K. Ueda | Ion pair formation in the NeAr dimer irradiated by monochromatic soft X-rays | 2017 | Chem. Phys. 482, 178 |
|||
| Abstract: {We investigated Ne+-Ar+ ion-pair formation which follows irradiation of the NeAr dimer by monochromatic soft X-rays. Using momentum-resolved electron-ion multicoincidence spectroscopy, we could unambiguously identify that the formation of the ion pair at photon energy of 200.5 eV proceeds via interatomic Coulombic decay (ICD) of the Ne+(2s-1)Ar inner-valence ionized and NeAr+ (3p-25d) ionization satellite state. Photoabsorption at higher photon energies of 268.2 eV and 888.7 eV leads to the emission of core electrons of Ar and Ne respectively, and to the subsequent local Auger decay process. We demonstrate that at these energies the ion pair formation originating in the doubly ionized Ar L-MM and Ne K-LL Auger final states proceeds mostly via radiative charge transfer and charge transfer driven by non-adiabatic coupling mechanisms.} | ||||||
BibTeX:
@article{Ouchi17b,
author = {Ouchi, T. and Stumpf, V. and Miteva, T. and Fukuzawa, H. and Sakai, K. and Liu, X.-J. and Mazza, T. and Schöffler, M. and Iwayama, H. and Nagaya, K. and Tamenori, Y. and Saito, N. and Kuleff, A. I. and Gokhberg, K. and Ueda, K.},
title = {{Ion pair formation in the NeAr dimer irradiated by monochromatic soft X-rays}},
journal = {Chem. Phys.},
publisher = {Elsevier},
year = {2017},
volume = {482},
pages = {178},
numpages = {7},
note = {experiment & theory},
doi = {https://doi.org/10.1016/j.chemphys.2016.09.032}
}
|
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| D. Hollas, M.N. Pohl, R. Seidel, E.F. Aziz, P. Slavíček & B. Winter | Aqueous Solution Chemistry of Ammonium Cation in the Auger Time Window | 2017 | Sci. Rep. 7, 756 |
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| Abstract: {We report on chemical reactions triggered by core-level ionization of ammonium (NH+4) cation in aqueous solution. Based on a combination of photoemission experiments from a liquid microjet and high-level ab initio simulations, we identified simultaneous single and double proton transfer occurring on a very short timescale spanned by the Auger-decay lifetime. Molecular dynamics simulations indicate that the proton transfer to a neighboring water molecule leads to essentially complete formation of H3O+(aq) and core-ionized ammonia (NH+3)*(aq) within the ~7fs lifetime of the nitrogen 1s core hole. A second proton transfer leads to a transient structure with the proton shared between the remaining NH2 moiety and another water molecule in the hydration shell. These ultrafast proton transfers are stimulated by very strong hydrogen bonds between the ammonium cation and water. Experimentally, the proton transfer dynamics is identified from an emerging signal at the high-kinetic energy side of the Auger-electron spectrum in analogy to observations made for other hydrogen-bonded aqueous solutions. The present study represents the most pronounced charge separation observed upon core ionization in liquids so far.} | ||||||
BibTeX:
@article{Hollas17,
author = {Hollas, D. and Pohl, M. N. and Seidel, R. and Aziz, E. F. and Slavíček, P. and Winter, B.},
title = {{Aqueous Solution Chemistry of Ammonium Cation in the Auger Time Window}},
journal = {Sci. Rep.},
publisher = {Nature Research},
year = {2017},
volume = {7},
pages = {756},
numpages = {10},
note = {experiment & theory},
doi = {https://doi.org/10.1038/s41598-017-00756-x}
}
|
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| E. Fasshauer, M. Förstel, M. Mucke, T. Arion & U. Hergenhahn | Theoretical and experimental investigation of Electron Transfer Mediated Decay in ArKr clusters | 2017 | Chem. Phys. 482, 226 |
|||
| Abstract: {We investigate the electronic decay of an Ar3s-1 vacancy in medium sized ArKr clusters. The only energetically accessible, radiationless decay mechanism is Electron Transfer Mediated Decay Three (ETMD3). Here, the argon vacancy is filled by an electron from one krypton atom, and the excess energy is transferred to a second krypton atom which consequently emits an electron. For the theoretical calculation of ETMD3 spectra, in a bottom-up approach, we study the dependence of the decay width on the geometry of elementary sets of three atoms, from which any cluster can be composed. We simulate the ETMD3 spectra of medium sized ArKr clusters and compare the resulting spectra to experimental ETMD electron spectra presented earlier (Phys. Rev. Lett. 106, 033402 (2011)) and in this work. We show that ETMD3 is the dominating relaxation mechanism for the cases studied here.} | ||||||
BibTeX:
@article{Fasshauer17,
author = {Fasshauer, E. and Förstel, M. and Mucke, M. and Arion, T. and Hergenhahn, U.},
title = {{Theoretical and experimental investigation of Electron Transfer Mediated Decay in ArKr clusters}},
journal = {Chem. Phys.},
publisher = {Elsevier},
year = {2017},
volume = {482},
pages = {226},
numpages = {13},
note = {experiment & theory},
doi = {https://doi.org/10.1016/j.chemphys.2016.09.006}
}
|
||||||
| S. Yan, P. Zhang, V. Stumpf, K. Gokhberg, X.C. Zhang, S. Xu, B. Li, L.L. Shen, X.L. Zhu, W.T. Feng, S.F. Zhang, D.M. Zhao & X. Ma | Interatomic relaxation processes induced in neon dimers by electron-impact ionization | 2018 | Phys. Rev. A 97, 010701(R) |
|||
| Abstract: {We report an experimental observation of the interatomic Coulombic decay (ICD) and radiative charge-transfer (RCT) processes in a Ne dimer (e,2e) following a 380-eV electron impact. By detecting the Ne+-Ne+ cation pair and one of the emitted electrons in coincidence, the fingerprint of the ICD process initiated by the inner-valence ionization of Ne is obtained. Furthermore, the experimental results and ab initio calculations together unambiguously confirm the occurrence of the RCT process, and we show that most of the low-energy electrons produced in ionization of the Ne dimers are due to the ICD, which strongly suggests the importance of the ICD in causing radiation damage in a biological medium.} | ||||||
BibTeX:
@article{Yan18,
author = {Yan, S. and Zhang, P. and Stumpf, V. and Gokhberg, K. and Zhang, X. C. and Xu, S. and Li, B. and Shen, L. L. and Zhu, X. L. and Feng, W. T. and Zhang, S. F. and Zhao, D. M. and Ma, X.},
title = {{Interatomic relaxation processes induced in neon dimers by electron-impact ionization}},
journal = {Phys. Rev. A},
publisher = {American Physical Society},
year = {2018},
volume = {97},
pages = {010701(R)},
numpages = {5},
note = {experiment & theory},
doi = {https://doi.org/10.1103/PhysRevA.97.010701}
}
|
||||||
| S. Xu, D. Guo, X. Ma, X. Zhu, W. Feng, S. Yan, D. Zhao, Y. Gao, S. Zhang, X. Ren, Y. Zhao, Z. Xu, A. Dorn, L.S. Cederbaum & N.V. Kryzhevoi | Damaging Intermolecular Energy and Proton Transfer Processes in Alpha-Particle-Irradiated Hydrogen-Bonded Systems | 2018 | Angew. Chem. Int. Ed. 57, 17023 |
|||
| Abstract: {Although the biological hazard of alpha-particle radiation is well-recognized, the respective molecular mechanisms of biodamage are still far from being understood. Irreparable lesions in biomolecules may not only have mechanical origin but also appear due to various electronic and nuclear relaxation processes of ionized states produced by an alpha-particle impact. Two such processes were identified in the present study by considering an acetylene dimer, a biologically relevant system possessing an intermolecular hydrogen bond. The first process is the already well-established intermolecular Coulombic decay of inner-valence-ionized states. The other one is a novel relaxation mechanism of dicationic states involving intermolecular proton transfer. Both processes are very fast and trigger Coulomb explosion of the dimer due to creation of charge-separated states. These processes are general and predicted to occur also in alpha-particle-irradiated nucleobase pairs in DNA molecules.} | ||||||
BibTeX:
@article{Xu18,
author = {Xu, S. and Guo, D. and Ma, X. and Zhu, X. and Feng, W. and Yan, S. and Zhao, D. and Gao, Y. and Zhang, S. and Ren, X. and Zhao, Y. and Xu, Z. and Dorn, A. and Cederbaum, L. S. and Kryzhevoi, N. V.},
title = {{Damaging Intermolecular Energy and Proton Transfer Processes in Alpha-Particle-Irradiated Hydrogen-Bonded Systems}},
journal = {Angew. Chem. Int. Ed.},
publisher = {Wiley-VCH},
year = {2018},
volume = {57},
issue = {52},
pages = {17023},
numpages = {5},
note = {experiment & theory},
doi = {https://doi.org/10.1002/anie.201808898}
}
|
||||||
| C. Richter, D. Hollas, C.-M. Saak, M. Förstel, T. Miteva, M. Mucke, O. Björneholm, N. Sisourat, P. Slavíček & U. Hergenhahn | Competition between proton transfer and intermolecular Coulombic decay in water | 2018 | Nat. Commun. 9, 4988 |
|||
| Abstract: {Intermolecular Coulombic decay (ICD) is a ubiquitous relaxation channel of electronically excited states in weakly bound systems, ranging from dimers to liquids. As it is driven by electron correlation, it was assumed that it will dominate over more established energy loss mechanisms, for example fluorescence. Here, we use electron-electron coincidence spectroscopy to determine the efficiency of the ICD process after 2a1 ionization in water clusters. We show that this efficiency is surprisingly low for small water clusters and that it gradually increases to 40-50% for clusters with hundreds of water units. Ab initio molecular dynamics simulations reveal that proton transfer between neighboring water molecules proceeds on the same timescale as ICD and leads to a configuration in which the ICD channel is closed. This conclusion is further supported by experimental results from deuterated water. Combining experiment and theory, we infer an intrinsic ICD lifetime of 12-52 fs for small water clusters.} | ||||||
BibTeX:
@article{Richter18,
author = {Richter, C. and Hollas, D. and Saak, C.-M. and Förstel, M. and Miteva, T. and Mucke, M. and Björneholm, O. and Sisourat, N. and Slavíček, P. and Hergenhahn, U.},
title = {{Competition between proton transfer and intermolecular Coulombic decay in water}},
journal = {Nat. Commun.},
publisher = {Nature Research},
year = {2018},
volume = {9},
pages = {4988},
numpages = {8},
note = {experiment & theory},
doi = {https://doi.org/10.1038/s41467-018-07501-6}
}
|
||||||
| X. Ren, E. Wang, A.D. Skitnevskaya, A.B. Trofimov, K. Gokhberg & A. Dorn | Experimental evidence for ultrafast intermolecular relaxation processes in hydrated biomolecules | 2018 | Nat. Phys. 14, 1062 |
|||
| Abstract: {Cell and gene damage caused by ionizing radiation has been studied for many years. It is accepted that DNA lesions (single- and double-strand breaks, for example) are induced by secondary species such as radicals, ions and the abundant low-energy secondary electrons generated by the primary radiation. Particularly harmful are dense ionization clusters of several ionization processes within a volume typical for the biomolecular system. Here we report the observation of a damage mechanism in the form of a non-local autoionizing process called intermolecular Coulombic decay (ICD). It directly involves DNA constituents or other organic molecules in an aqueous environment. The products are two energetic ions and three reactive secondary electrons that can cause further damage in their vicinity. Hydrogen-bonded complexes that consist of one tetrahydrofuran (THF) molecule-a surrogate of deoxyribose in the DNA backbone-and one water molecule are used as a model system. After electron impact ionization of the water molecule in the inner-valence shell the vacancy is filled by an outer-valence electron. The released energy is transferred across the hydrogen bridge and leads to ionization of the neighbouring THF molecule. This energy transfer from water to THF is faster than the otherwise occurring intermolecular proton transfer. The signature of the ICD reaction is identified in triple-coincidence measurements of both ions and one of the final state electrons. These results could improve the understanding of radiation damage in biological tissue.} | ||||||
BibTeX:
@article{Ren18,
author = {Ren, X. and Wang, E. and Skitnevskaya, A. D. and Trofimov, A. B. and Gokhberg, K. and Dorn, A.},
title = {{Experimental evidence for ultrafast intermolecular relaxation processes in hydrated biomolecules}},
journal = {Nat. Phys.},
publisher = {Nature Research},
year = {2018},
volume = {14},
pages = {1062},
numpages = {6},
note = {experiment & theory},
doi = {https://doi.org/10.1038/s41567-018-0214-9}
}
|
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| A. Mhamdi, F. Trinter, C. Rauch, M. Weller, J. Rist, M. Waitz, J. Siebert, D. Metz, C. Janke, G. Kastirke, F. Wiegandt, T. Bauer, M. Tia, B. Cunha de Miranda, M. Pitzer, H. Sann, G. Schiwietz, M. Schöffler, M. Simon, K. Gokhberg, R. Dörner, T. Jahnke & Ph.V. Demekhin | Resonant interatomic Coulombic decay in HeNe: Electron angular emission distributions | 2018 | Phys. Rev. A 97, 053407 |
|||
| Abstract: {We present a joint experimental and theoretical study of resonant interatomic Coulombic decay (RICD) in HeNe employing high resolution cold target recoil ion momentum spectroscopy and ab initio electronic structure and nuclear dynamics calculations. In particular, laboratory- and molecular-frame angular emission distributions of RICD electrons are examined in detail. The exciting-photon energy-dependent anisotropy parameter β(ω), measured for decay events that populate bound HeNe+ ions, is in agreement with the calculations performed for the ground ionic state X2Σ½+. A contribution from the a2Π3/2 final ionic state is found to be negligible. For the He + Ne+ fragmentation channel, the observed laboratory-frame angular distribution of RICD electrons is explained by a slow homogeneous dissociation of bound vibrational levels of the final ionic state A2Π½ into vibrational continua of the lower lying states X2Σ½+ and a2Π3/2. Our calculations predict that the angular distributions of RICD electrons in the body-fixed dipole plane provide direct access to the electronic character (i.e., symmetry) of intermediate vibronic resonances. However, because of the very slow dissociation of the A2Π½ state, the molecular-frame angular distributions of RICD electrons in the He + Ne+ fragmentation channel are inaccessible to our coincidence experiment.} | ||||||
BibTeX:
@article{Mhamdi18,
author = {Mhamdi, A. and Trinter, F. and Rauch, C. and Weller, M. and Rist, J. and Waitz, M. and Siebert, J. and Metz, D. and Janke, C. and Kastirke, G. and Wiegandt, F. and Bauer, T. and Tia, M. and Cunha de Miranda, B. and Pitzer, M. and Sann, H. and Schiwietz, G. and Schöffler, M. and Simon, M. and Gokhberg, K. and Dörner, R. and Jahnke, T. and Demekhin, Ph. V.},
title = {{Resonant interatomic Coulombic decay in HeNe: Electron angular emission distributions}},
journal = {Phys. Rev. A},
publisher = {American Physical Society},
year = {2018},
volume = {97},
pages = {053407},
numpages = {9},
note = {experiment & theory},
doi = {https://doi.org/10.1103/PhysRevA.97.053407}
}
|
||||||
| A. Mhamdi, J. Rist, D. Aslitürk, M. Weller, N. Melzer, D. Trabert, M. Kircher, I. Vela-Pérez, J. Siebert, S. Eckart, S. Grundmann, G. Kastirke, M. Waitz, A. Khan, M.S. Schöffler, F. Trinter, R. Dörner, T. Jahnke & Ph.V. Demekhin | Breakdown of the Spectator Concept in Low-Electron-Energy Resonant Decay Processes | 2018 | Phys. Rev. Lett. 121, 243002 |
|||
| Abstract: {We suggest that low-energy electrons, released by resonant decay processes, experience substantial scattering on the electron density of excited electrons, which remain a spectator during the decay. As a result, the angular emission distribution is altered significantly. This effect is expected to be a common feature of low-energy secondary electron emission. In this Letter, we exemplify our idea by examining the spectator resonant interatomic Coulombic decay of Ne dimers. Our theoretical predictions are confirmed by a corresponding coincidence experiment.} | ||||||
BibTeX:
@article{Mhamdi18b,
author = {Mhamdi, A. and Rist, J. and Aslitürk, D. and Weller, M. and Melzer, N. and Trabert, D. and Kircher, M. and Vela-Pérez, I. and Siebert, J. and Eckart, S. and Grundmann, S. and Kastirke, G. and Waitz, M. and Khan, A. and Schöffler, M. S. and Trinter, F. and Dörner, R. and Jahnke, T. and Demekhin, Ph. V.},
title = {{Breakdown of the Spectator Concept in Low-Electron-Energy Resonant Decay Processes}},
journal = {Phys. Rev. Lett.},
publisher = {American Physical Society},
year = {2018},
volume = {121},
pages = {243002},
numpages = {6},
note = {experiment & theory},
doi = {https://doi.org/10.1103/PhysRevLett.121.243002}
}
|
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| Y. Kumagai, H. Fukuzawa, K. Motomura, D. Iablonskyi, K. Nagaya, S. Wada, Y. Ito, T. Takanashi, Y. Sakakibara, D. You, T. Nishiyama, K. Asa, Y. Sato, T. Umemoto, K. Kariyazono, E. Kukk, K. Kooser, Ch. Nicolas, C. Miron, T. Asavei, L. Neagu, M.S. Schöffler, G. Kastirke, X. Liu, S. Owada, T. Katayama, T. Togashi, K. Tono, M. Yabashi, N.V. Golubev, K. Gokhberg, L.S. Cederbaum, A.I. Kuleff & K. Ueda | Following the Birth of a Nanoplasma Produced by an Ultrashort Hard-X-Ray Laser in Xenon Clusters | 2018 | Phys. Rev. X 8, 031034 |
|||
| Abstract: {X-ray free-electron lasers (XFELs) made available a new regime of x-ray intensities, revolutionizing the ultrafast structure determination and laying the foundations of the novel field of nonlinear x-ray optics. Although earlier studies revealed nanoplasma formation when an XFEL pulse interacts with any nanometer-scale matter, the formation process itself has never been decrypted and its timescale was unknown. Here we show that time-resolved ion yield measurements combined with a near-infrared laser probe reveal a surprisingly ultrafast population (∼12 fs), followed by a slower depopulation (∼250 fs) of highly excited states of atomic fragments generated in the process of XFEL-induced nanoplasma formation. Inelastic scattering of Auger electrons and interatomic Coulombic decay are suggested as the mechanisms populating and depopulating, respectively, these excited states. The observed response occurs within the typical x-ray pulse durations and affects x-ray scattering, thus providing key information on the foundations of x-ray imaging with XFELs.} | ||||||
BibTeX:
@article{Kumagai18,
author = {Kumagai, Y. and Fukuzawa, H. and Motomura, K. and Iablonskyi, D. and Nagaya, K. and Wada, S. and Ito, Y. and Takanashi, T. and Sakakibara, Y. and You, D. and Nishiyama, T. and Asa, K. and Sato, Y. and Umemoto, T. and Kariyazono, K. and Kukk, E. and Kooser, K. and Nicolas, Ch. and Miron, C. and Asavei, T. and Neagu, L. and Schöffler, M. S. and Kastirke, G. and Liu, X. and Owada, S. and Katayama, T. and Togashi, T. and Tono, K. and Yabashi, M. and Golubev, N. V. and Gokhberg, K. and Cederbaum, L. S. and Kuleff, A. I. and Ueda, K.},
title = {{Following the Birth of a Nanoplasma Produced by an Ultrashort Hard-X-Ray Laser in Xenon Clusters}},
journal = {Phys. Rev. X},
publisher = {American Physical Society},
year = {2018},
volume = {8},
pages = {031034},
numpages = {8},
note = {experiment & theory},
doi = {https://doi.org/10.1103/PhysRevX.8.031034}
}
|
||||||
| S. Kazandjian, J. Rist, M. Weller, F. Wiegandt, D. Aslitürk, S. Grundmann, M. Kircher, G. Nalin, D. Pitters, I. Vela Pérez, M. Waitz, G. Schiwietz, B. Griffin, J.B. Williams, R. Dörner, M. Schöffler, T. Miteva, F. Trinter, T. Jahnke & N. Sisourat | Frustrated Coulomb explosion of small helium clusters | 2018 | Phys. Rev. A 98, 050701(R) |
|||
| Abstract: {Almost 10 years ago, energetic neutral hydrogen atoms were detected after a strong-field double ionization of H2. This process, called “frustrated tunneling ionization”, occurs when an ionized electron is recaptured after being driven back to its parent ion by the electric field of a femtosecond laser. In the present study we demonstrate that a related process naturally occurs in clusters without the need of an external field: we observe a charge hopping that occurs during a Coulomb explosion of a small helium cluster, which leads to an energetic neutral helium atom. This claim is supported by theoretical evidence. As an analog to frustrated tunneling ionization, we term this process “frustrated Coulomb explosion”.} | ||||||
BibTeX:
@article{Kazandjian18,
author = {Kazandjian, S. and Rist, J. and Weller, M. and Wiegandt, F. and Aslitürk, D. and Grundmann, S. and Kircher, M. and Nalin, G. and Pitters, D. and Vela Pérez, I. and Waitz, M. and Schiwietz, G. and Griffin, B. and Williams, J. B. and Dörner, R. and Schöffler, M. and Miteva, T. and Trinter, F. and Jahnke, T. and Sisourat, N.},
title = {{Frustrated Coulomb explosion of small helium clusters}},
journal = {Phys. Rev. A},
publisher = {American Physical Society},
year = {2018},
volume = {98},
issue = {5},
pages = {050701(R)},
numpages = {5},
note = {experiment & theory},
doi = {https://doi.org/10.1103/PhysRevA.98.050701}
}
|
||||||
| F. Wiegandt, F. Trinter, K. Henrichs, D. Metz, M. Pitzer, M. Waitz, E. Jabbour al Maalouf, C. Janke, J. Rist, N. Wechselberger, T. Miteva, S. Kazandjian, M. Schöffler, N. Sisourat, T. Jahnke & R. Dörner | Direct observation of interatomic Coulombic decay and subsequent ion-atom scattering in helium nanodroplets | 2019 | Phys. Rev. A 100, 022707 |
|||
| Abstract: {We report on the experimental observation of interatomic Coulombic decay (ICD) in pure 4He nanoclusters of mean sizes between N ∼ 5000 and 30000 and the subsequent scattering of energetic He+ fragments inside the neutral cluster by using cold target recoil ion momentum spectroscopy. ICD is induced in He clusters by using vacuum ultraviolet light of hν = 67eV from the BESSY II synchrotron. The electronic decay creates two neighboring ions in the cluster at a well-defined distance. The measured fragment energies and angular correlations show that a main energy loss mechanism of these ions inside the cluster is a single hard binary collision with one atom of the cluster.} | ||||||
BibTeX:
@article{Wiegandt19,
author = {Wiegandt, F. and Trinter, F. and Henrichs, K. and Metz, D. and Pitzer, M. and Waitz, M. and Jabbour al Maalouf, E. and Janke, C. and Rist, J. and Wechselberger, N. and Miteva, T. and Kazandjian, S. and Schöffler, M. and Sisourat, N. and Jahnke, T. and Dörner, R.},
title = {{Direct observation of interatomic Coulombic decay and subsequent ion-atom scattering in helium nanodroplets}},
journal = {Phys. Rev. A},
publisher = {American Physical Society},
year = {2019},
volume = {100},
issue = {2},
pages = {022707},
numpages = {6},
note = {experiment & theory},
doi = {https://doi.org/10.1103/PhysRevA.100.022707}
}
|
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| G. Schmid, K. Schnorr, S. Augustin, S. Meister, H. Lindenblatt, F. Trost, Y. Liu, T. Miteva, M. Gisselbrecht, S. Düsterer, H. Redlin, R. Treusch, K. Gokhberg, A.I. Kuleff, L.S. Cederbaum, C.D. Schröter, T. Pfeifer & R. Moshammer | Tracing charge transfer in argon dimers by XUV-pump IR-probe experiments at FLASH | 2019 | J. Chem. Phys. 151, 084314 |
|||
| Abstract: {Charge transfer (CT) at avoided crossings of excited ionized states of argon dimers is observed using a two-color pump-probe experiment at the free-electron laser in Hamburg (FLASH). The process is initiated by the absorption of three 27-eV-photons from the pump pulse, which leads to the population of Ar2+*-Ar states. Due to nonadiabatic coupling between these one-site doubly ionized states and two-site doubly ionized states of the type Ar+*-Ar+, CT can take place leading to the population of the latter states. The onset of this process is probed by a delayed infrared (800 nm) laser pulse. The latter ionizes the dimers populating repulsive Ar2+-Ar+ states, which then undergo a Coulomb explosion. From the delay-dependent yields of the obtained Ar2+ and Ar+ ions, the lifetime of the charge-transfer process is extracted. The obtained experimental value of (531 ± 136) fs agrees well with the theoretical value computed from Landau-Zener probabilities.} | ||||||
BibTeX:
@article{Schmidt19,
author = {Schmid, G. and Schnorr, K. and Augustin, S. and Meister, S. and Lindenblatt, H. and Trost, F. and Liu, Y. and Miteva, T. and Gisselbrecht, M. and Düsterer, S. and Redlin, H. and Treusch, R. and Gokhberg, K. and Kuleff, A. I. and Cederbaum, L. S. and Schröter, C. D. and Pfeifer, T. and Moshammer, R.},
title = {{Tracing charge transfer in argon dimers by XUV-pump IR-probe experiments at FLASH}},
journal = {J. Chem. Phys.},
publisher = {AIP},
year = {2019},
volume = {151},
issue = {8},
pages = {084314},
numpages = {8},
note = {experiment & theory},
doi = {https://doi.org/10.1063/1.5116234}
}
|
||||||
| R. Püttner, T. Marchenko, R. Guillemin, L. Journel, G. Goldsztejn, D. Céolin, O. Takahashi, K. Ueda, A.F. Lago, M.N. Piancastelli & M. Simon | Si 1s-1, 2s-1, and 2p-1 lifetime broadening of SiX4 (X = F,Cl,Br,CH3) molecules: SiF4 anomalous behaviour reassessed | 2019 | Phys. Chem. Chem. Phys. 21, 8827 |
|||
| Abstract: {The Si 1s-1, Si 2s-1, and Si 2p-1 photoelectron spectra of the SiX4 molecules with X=F,Cl,Br,CH3 were measured. From these spectra the Si 1s-1 and Si 2s-1 lifetime broadenings were determined, revealing a significantly larger value for the Si 2s-1 core hole of SiF4 than for the same core hole of the other molecules of the sequence. This finding is in line with the results of the Si 2p-1 core holes of a number of SiX4 molecules, with an exceptionally large broadening for SiF4. For the Si 2s-1 core hole of SiF4 the difference to the other SiX4 molecules can be explained in terms of Interatomic Coulomb Decay (ICD)-like processes. For the Si 2p-1 core hole of SiF4 the estimated values for the sum of the Intraatomic Auger Electron Decay (IAED) and ICD-like processes are too small to explain the observed linewidth. However, results of the given discussion render for SiF4 significant contributions from Electron Transfer Mediated Decay (ETMD)-like processes at least plausible. Our investigation suggests that for the S 2s-1 core hole of SF6 as well as the P 2s-1 core hole of PF3 and PF5 ICD-like processes cause a significant contributions to the lifetime. For significant ETMD-like contributions to the lifetime width the Ge 3d-1 core hole of GeF4 could be identified as a good candidate.} | ||||||
BibTeX:
@article{Puettner19,
author = {Püttner, R. and Marchenko, T. and Guillemin, R. and Journel, L. and Goldsztejn, G. and Céolin, D. and Takahashi, O. and Ueda, K. and Lago, A. F. and Piancastelli, M. N. and Simon, M.},
title = {{Si 1s-1, 2s-1, and 2p-1 lifetime broadening of SiX4 (X = F,Cl,Br,CH3) molecules: SiF4 anomalous behaviour reassessed}},
journal = {Phys. Chem. Chem. Phys.},
publisher = {RSC},
year = {2019},
volume = {21},
pages = {8827},
numpages = {10},
note = {experiment & theory},
doi = {https://doi.org/10.1039/C8CP07369D}
}
|
||||||
| L.B. Ltaief, M. Shcherbinin, S. Mandal, S.R. Krishnan, A.C. LaForge, R. Richter, S. Turchini, N. Zema, T. Pfeifer, E. Fasshauer, N. Sisourat & M. Mudrich | Charge Exchange Dominates Long-Range Interatomic Coulombic Decay of Excited Metal-Doped Helium Nanodroplets | 2019 | J. Phys. Chem. Lett. 10, 6904 |
|||
| Abstract: {Atoms and molecules attached to rare-gas clusters are ionized by an interatomic autoionization process traditionally termed “Penning ionization” when the host cluster is resonantly excited. Here we analyze this process in the light of the interatomic Coulombic decay (ICD) mechanism, which usually contains a contribution from charge exchange at a short interatomic distance and one from virtual photon transfer at a large interatomic distance. For helium (He) nanodroplets doped with alkali metal atoms (Li, Rb), we show that long-range and short-range contributions to the interatomic autoionization can be clearly distinguished by detecting electrons and ions in coincidence. Surprisingly, ab initio calculations show that even for alkali metal atoms floating in dimples at a large distance from the nanodroplet surface, autoionization is largely dominated by charge-exchange ICD. Furthermore, the measured electron spectra manifest the ultrafast internal relaxation of the droplet mainly into the 1s2s1S state and partially into the metastable 1s2s3S state.} | ||||||
BibTeX:
@article{Ltaief19,
author = {Ltaief, L. B. and Shcherbinin, M. and Mandal, S. and Krishnan, S. R. and LaForge, A. C. and Richter, R. and Turchini, S. and Zema, N. and Pfeifer, T. and Fasshauer, E. and Sisourat, N. and Mudrich, M.},
title = {{Charge Exchange Dominates Long-Range Interatomic Coulombic Decay of Excited Metal-Doped Helium Nanodroplets}},
journal = {J. Phys. Chem. Lett.},
publisher = {American Chemical Society},
year = {2019},
volume = {10},
issue = {21},
pages = {6904},
numpages = {6},
note = {experiment & theory},
doi = {https://doi.org/10.1021/acs.jpclett.9b02726}
}
|
||||||
| H. Fukuzawa, T. Takanashi, E. Kukk, K. Motomura, S. Wada, K. Nagaya, Y. Ito, T. Nishiyama, Ch. Nicolas, Y. Kumagai, D. Iablonskyi, S. Mondal, T. Tachibana, D. You, S. Yamada, Y. Sakakibara, K. Asa, Y. Sato, T. Sakai, K. Matsunami, T. Umemoto, K. Kariyazono, S. Kajimoto, H. Sotome, P. Johnsson, M.S. Schöffler, G. Kastirke, K. Kooser, X.-J. Liu, Th. Asavei, L. Neagu, S. Molodtsov, K. Ochiai, M. Kanno, K. Yamazaki, S. Owada, K. Ogawa, T. Katayama, T. Togashi, K. Tono, M. Yabashi, A. Ghosh, K. Gokhberg, L.S. Cederbaum, A.I. Kuleff, H. Fukumura, N. Kishimoto, A. Rudenko, C. Miron, H. Kono & K. Ueda | Real-time observation of X-ray-induced intramolecular and interatomic electronic decay in CH2I2 | 2019 | Nat. Commun. 10, 2186 |
|||
| Abstract: {The increasing availability of X-ray free-electron lasers (XFELs) has catalyzed the development of single-object structural determination and of structural dynamics tracking in real-time. Disentangling the molecular-level reactions triggered by the interaction with an XFEL pulse is a fundamental step towards developing such applications. Here we report real-time observations of XFEL-induced electronic decay via short-lived transient electronic states in the diiodomethane molecule, using a femtosecond near-infrared probe laser. We determine the lifetimes of the transient states populated during the XFEL-induced Auger cascades and find that multiply charged iodine ions are issued from short-lived (∼20fs) transient states, whereas the singly charged ones originate from significantly longer-lived states (∼100fs). We identify the mechanisms behind these different time scales: contrary to the short-lived transient states which relax by molecular Auger decay, the long-lived ones decay by an interatomic Coulombic decay between two iodine atoms, during the molecular fragmentation.} | ||||||
BibTeX:
@article{Fukuzawa19_b,
author = {Fukuzawa, H. and Takanashi, T. and Kukk, E. and Motomura, K. and Wada, S. and Nagaya, K. and Ito, Y. and Nishiyama, T. and Nicolas, Ch. and Kumagai, Y. and Iablonskyi, D. and Mondal, S. and Tachibana, T. and You, D. and Yamada, S. and Sakakibara, Y. and Asa, K. and Sato, Y. and Sakai, T. and Matsunami, K. and Umemoto, T. and Kariyazono, K. and Kajimoto, S. and Sotome, H. and Johnsson, P. and Schöffler, M. S. and Kastirke, G. and Kooser, K. and Liu, X.-J. and Asavei, Th. and Neagu, L. and Molodtsov, S. and Ochiai, K. and Kanno, M. and Yamazaki, K. and Owada, S. and Ogawa, K. and Katayama, T. and Togashi, T. and Tono, K. and Yabashi, M. and Ghosh, A. and Gokhberg, K. and Cederbaum, L. S. and Kuleff, A. I. and Fukumura, H. and Kishimoto, N. and Rudenko, A. and Miron, C. and Kono, H. and Ueda, K.},
title = {{Real-time observation of X-ray-induced intramolecular and interatomic electronic decay in CH2I2}},
journal = {Nat. Commun.},
publisher = {Nature Research},
year = {2019},
volume = {10},
pages = {2186},
numpages = {8},
note = {experiment & theory},
doi = {https://doi.org/10.1038/s41467-019-10060-z}
}
|
||||||
| Y. Ovcharenko, A.C. LaForge, B. Langbehn, O. Plekan, R. Cucini, P. Finetti, P. O'Keeffe, D. Iablonskyi, T. Nishiyama, K. Ueda, P. Piseri, M. DiFraia, R. Richter, M. Coreno, C. Callegari, K.C. Prince, F. Stienkemeier, T. Möller & M. Mudrich | Autoionization dynamics of He nanodroplets resonantly excited by intense XUV laser pulses | 2020 | New J. Phys. 22, 083043 |
|||
| Abstract: {The ionization dynamics of helium droplets irradiated by intense, femtosecond extreme ultraviolet (XUV) pulses is investigated in detail by photoelectron spectroscopy. Helium droplets are resonantly excited to atomic-like 2p states with a photon energy of 21.5 eV and autoionize by interatomic Coulombic decay (ICD). A complex evolution of the electron spectra as a function of droplet size (250 to 106 He atoms per droplet) and XUV intensity (109 - 1012 W/cm2) is observed, ranging from narrow atomic-like peaks that are due to binary autoionization, to an unstructured feature characteristic of electron emission from a nanoplasma. The experimental results are analyzed and interpreted with the help of a numerical simulation based on rate equations taking into account all relevant processes - multi-step ionization, electronic relaxation, ICD, secondary inelastic collisions, desorption of electronically excited atoms, and collective autoionization (CAI).} | ||||||
BibTeX:
@article{Ovcharenko20,
author = {Ovcharenko, Y. and LaForge, A. C. and Langbehn, B. and Plekan, O. and Cucini, R. and Finetti, P. and O'Keeffe, P. and Iablonskyi, D. and Nishiyama, T. and Ueda, K. and Piseri, P. and DiFraia, M. and Richter, R. and Coreno, M. and Callegari, C. and Prince, K. C. and Stienkemeier, F. and Möller, T. and Mudrich, M.},
title = {{Autoionization dynamics of He nanodroplets resonantly excited by intense XUV laser pulses}},
journal = {New J. Phys.},
publisher = {IOP},
year = {2020},
volume = {22},
pages = {083043},
note = {experiment & theory},
doi = {https://doi.org/10.1088/1367-2630/ab9554}
}
|
||||||
| A. Mhamdi, J. Rist, T. Havermeier, R. Dörner, T. Jahnke & Ph.V. Demekhin | Theoretical study of molecular-frame angular emission distributions of electrons emitted by interatomic Coulombic decay from helium dimers | 2020 | Phys. Rev. A 101, 023404 |
|||
| Abstract: {Molecular frame angular distributions of electrons released by interatomic Coulombic decay of He+*(2ℓ)-He states are studied theoretically by means of electronic structure and nonadiabatic nuclear dynamics calculations. In previous experimental work [Phys. Rev. A 82, 063405 (2010)], distinct variations of the angular emission patterns have been observed for different ranges of kinetic-energy release of the fragment ions. Good agreement between the presently computed and these measured angular distributions can be achieved by assuming nonequal populations of 2Σ+g/u and 2Πg/u decaying electronic states via initial shake-up ionization of the dimers.} | ||||||
BibTeX:
@article{Mhamdi20,
author = {Mhamdi, A. and Rist, J. and Havermeier, T. and Dörner, R. and Jahnke, T. and Demekhin, Ph. V.},
title = {{Theoretical study of molecular-frame angular emission distributions of electrons emitted by interatomic Coulombic decay from helium dimers}},
journal = {Phys. Rev. A},
publisher = {American Physical Society},
year = {2020},
volume = {101},
issue = {2},
pages = {023404},
numpages = {6},
note = {experiment & theory},
doi = {https://doi.org/10.1103/PhysRevA.101.023404}
}
|
||||||
| L.B. Ltaief, M. Shcherbinin, S. Mandal, S.R. Krishnan, R. Richter, T. Pfeifer, M. Bauer, A. Ghosh, M. Mudrich, K. Gokhberg & A.C. LaForge | Electron transfer mediated decay of alkali dimers attached to He nanodroplets | 2020 | Phys. Chem. Chem. Phys. 22, 8557 |
|||
| Abstract: {Alkali metal dimers attached to the surface of helium nanodroplets are found to be efficiently doubly ionized by electron transfer mediated decay (ETMD) when photoionizing the helium droplets. This process is evidenced by detecting in coincidence two energetic ions created by Coulomb explosion and one low-kinetic energy electron. The kinetic energy spectra of ions and electrons are reproduced by simple model calculations based on diatomic potential energy curves, and are in agreement with ab initio calculations for the He–Na2 and He–KRb systems. This work demonstrates that ETMD is an important decay channel in heterogeneous nanosystems exposed to ionizing radiation.} | ||||||
BibTeX:
@article{Ltaief20,
author = {Ltaief, L. B. and Shcherbinin, M. and Mandal, S. and Krishnan, S. R. and Richter, R. and Pfeifer, T. and Bauer, M. and Ghosh, A. and Mudrich, M. and Gokhberg, K. and LaForge, A.C. },
title = {{Electron transfer mediated decay of alkali dimers attached to He nanodroplets}},
journal = {Phys. Chem. Chem. Phys.},
publisher = {RSC},
year = {2020},
volume = {22},
pages = {8557},
numpages = {8},
note = {experiment & theory},
doi = {https://doi.org/10.1039/d0cp00256a}
}
|
||||||
| T. Jahnke, U. Hergenhahn, B. Winter, R. Dörner, U. Frühling, P.V. Demekhin, K. Gokhberg, Cederbaum, S.L., A. Ehresmann, A. Knie & A. Dreuw | Interatomic and Intermolecular Coulombic Decay | 2020 | Chem. Rev. 120, 11295 |
|||
| Abstract: {Interatomic or intermolecular Coulombic decay (ICD) is a nonlocal electronic decay mechanism occurring in weakly bound matter. In an ICD process, energy released by electronic relaxation of an excited atom or molecule leads to ionization of a neighboring one via Coulombic electron interactions. ICD has been predicted theoretically in the mid nineties of the last century, and its existence has been confirmed experimentally approximately ten years later. Since then, a number of fundamental and applied aspects have been studied in this quickly growing field of research. This review provides an introduction to ICD and draws the connection to related energy transfer and ionization processes. The theoretical approaches for the description of ICD as well as the experimental techniques developed and employed for its investigation are described. The existing body of literature on experimental and theoretical studies of ICD processes in different atomic and molecular systems is reviewed.} | ||||||
BibTeX:
@article{Jahnke20,
author = {Jahnke, T. and Hergenhahn, U. and Winter, B. and Dörner, R. and Frühling, U. and Demekhin, P. V. and Gokhberg, K. and Cederbaum, and L. S. and Ehresmann, A. and Knie, A. and Dreuw, A.},
title = {{Interatomic and Intermolecular Coulombic Decay}},
journal = {Chem. Rev.},
publisher = {American Chemical Society},
year = {2020},
volume = {120},
issue = {20},
pages = {11295},
numpages = {75},
note = {experiment & theory},
doi = {https://doi.org/10.1021/acs.chemrev.0c00106}
}
|
||||||
| C.W. Hogle, L. Martin, X.-M. Tong, K. Ueda, T. Miteva, L.S. Cederbaum, H.C. Kapteyn, M.M. Murnane & P. Ranitovic | Laser-Enabled Control of Interatomic-Coulomb-Decay Dynamics | 2020 | The 22nd International Conference on Ultrafast Phenomena 2020 ,The 22nd International Conference on Ultrafast Phenomena 2020 Tu4A.44 |
|||
| Abstract: {Interatomic-Coulombic-Decay (ICD) processes play an important role in the interaction of X-rays with biological systems. Here, we present the first successful experimental demonstration that enables and precisely times the outcome of an ICD process in an argon dimer, utilizing ultrafast XUV and IR radiation.} | ||||||
BibTeX:
@inproceedings{Hogle20,
author = {C. W. Hogle and L. Martin and X.-M. Tong and K. Ueda and T. Miteva and L. S. Cederbaum and H. C. Kapteyn and M. M. Murnane and P. Ranitovic},
title = {{Laser-Enabled Control of Interatomic-Coulomb-Decay Dynamics}},
booktitle = {The 22nd International Conference on Ultrafast Phenomena 2020},
journal = {The 22nd International Conference on Ultrafast Phenomena 2020},
publisher = {Optica Publishing Group},
year = {2020},
pages = {Tu4A.44},
note = {experiment & theory},
doi = {https://doi.org/10.1364/UP.2020.Tu4A.44}
}
|
||||||
| A. Hans, C. Küstner-Wetekam, Ph. Schmidt, C. Ozga, X. Holzapfel, H. Otto, C. Zindel, C. Richter, L.S. Cederbaum, A. Ehresmann, U. Hergenhahn, N.V. Kryzhevoi & A. Knie | Core-level interatomic Coulombic decay in van der Waals clusters | 2020 | Phys. Rev. Res. 2, 012022(R) |
|||
| Abstract: {We report on the experimental observation of the direct decay of a core vacancy in van der Waals clusters by emission of a fast electron from a neighboring atom. The process can be regarded as an interatomic Coulombic decay of core holes (core-level ICD). We identify it unambiguously by electron-electron and electron-electron-photon coincidence spectroscopy of the decay of 2p vacancies in Ar clusters. While several earlier works reported the absence of this channel, we find core-level ICD to be of considerable significance and quantify the branching ratio of this nonlocal electron emission to conventional local Auger decay as (0.8±0.2)%. Our results are supported by calculations on smaller clusters and show a reasonable agreement. This report on a successfully performed electron-electron-photon coincidence experiment provides a perspective for explorations of matter exposed to ionizing radiation. The observed core-level ICD is proposed to be of general importance for studies on charge redistribution after core-level photoionization where van der Waals clusters are often used as prototype systems.} | ||||||
BibTeX:
@article{Hans20,
author = {Hans, A. and Küstner-Wetekam, C. and Schmidt, Ph. and Ozga, C. and Holzapfel, X. and Otto, H. and Zindel, C. and Richter, C. and Cederbaum, L. S. and Ehresmann, A. and Hergenhahn, U. and Kryzhevoi, N. V. and Knie, A.},
title = {{Core-level interatomic Coulombic decay in van der Waals clusters}},
journal = {Phys. Rev. Res.},
publisher = {American Physical Society},
year = {2020},
volume = {2},
issue = {1},
pages = {012022(R)},
numpages = {6},
note = {experiment & theory},
doi = {https://doi.org/10.1103/PhysRevResearch.2.012022}
}
|
||||||
| S. Creutzburg, J. Schwestka, A. Niggas, H. Inani, M. Tripathi, A. George, R. Heller, R. Kozubek, L. Madauß, N. McEvoy, S. Facsko, J. Kotakoski, M. Schleberger, A. Turchanin, P.L. Grande, F. Aumayr & R.A. Wilhelm | Vanishing influence of the band gap on the charge exchange of slow highly charged ions in freestanding single-layer MoS2 | 2020 | Phys. Rev. B 102, 045408 |
|||
| Abstract: {Charge exchange and kinetic energy loss of slow highly charged xenon ions transmitted through freestanding monolayer MoS2 are studied. Two distinct exit charge state distributions, characterized by high and low charge states, are observed. They are accompanied by smaller and larger kinetic energy losses, as well as scattering angles, respectively. High charge exchange is attributed to two-center neutralization processes, which take place in close impact collisions with the target atoms. Experimental findings are compared to graphene as a target material and simulations based on a time-dependent scattering potential model. Independent of the target material, experimentally observed charge exchange can be modeled by the same electron capture and de-excitation rates for MoS2 and graphene. A common dependence of the kinetic energy loss on the charge exchange for MoS2 as well as graphene is also observed. Considering the similarities of the zero band-gap material graphene and the 1.9 eV band-gap material MoS2, we suggest that electron transport on the femtosecond timescale is dominated by the strong influence of the ion's Coulomb potential in contrast to the dispersion defined by the material's band structure.} | ||||||
BibTeX:
@article{Creutzburg20,
author = {Creutzburg, S. and Schwestka, J. and Niggas, A. and Inani, H. and Tripathi, M. and George, A. and Heller, R. and Kozubek, R. and Madauß, L. and McEvoy, N. and Facsko, S. and Kotakoski, J. and Schleberger, M. and Turchanin, A. and Grande, P. L. and Aumayr, F. and Wilhelm, R. A.},
title = {{Vanishing influence of the band gap on the charge exchange of slow highly charged ions in freestanding single-layer MoS2}},
journal = {Phys. Rev. B},
publisher = {American Physical Society},
year = {2020},
volume = {102},
issue = {4},
pages = {045408},
numpages = {8},
note = {experiment & theory},
doi = {https://doi.org/10.1103/PhysRevB.102.045408}
}
|
||||||
| D. Bhattacharya & T. Kirchner | Strengthening the case for interatomic Coulomb decay as a subdominant reaction channel in slow O3+−Ne2 collisions with independent-atom-model coupled-channel calculations | 2020 | Phys. Rev. A 102, 062816 |
|||
| Abstract: {We report on electron removal calculations for 2.81 keV/amu Li3+ and O3+ ion collisions with neon dimers. The target is described as two independent neon atoms fixed at the dimer's equilibrium bond length, whose electrons are subjected to the time-dependent bare and screened Coulomb potentials of the classically moving Li3+ and O3+ projectile ions, respectively. Three mutually perpendicular orientations of the dimer with respect to the rectilinear projectile trajectories are considered and collision events for the two ion-atom subsystems are combined in an impact parameter by impact parameter fashion and are orientation averaged to calculate probabilities and cross sections for the ion-dimer system. The coupled-channel two-center basis generator method is used to solve the ion-atom collision problems. We concentrate the ion-dimer analysis on one-electron and two-electron removal processes which can be associated with interatomic Coulomb decay, Coulomb explosion, and radiative charge transfer. We find that the calculated relative yields are in fair agreement with recent experimental data for O3+−Ne2 collisions if we represent the projectile by a screened Coulomb potential, but disagree markedly for a bare Coulomb potential, i.e., for Li3+ impact. In particular, our calculations suggest that interatomic Coulomb decay is a significant reaction channel in the former case only, since capture of a Ne(2s) electron to form hydrogenlike Li2+ is unlikely.} | ||||||
BibTeX:
@article{Bhattacharya20,
author = {Bhattacharya, D. and Kirchner, T.},
title = {{Strengthening the case for interatomic Coulomb decay as a subdominant reaction channel in slow O3+−Ne2 collisions with independent-atom-model coupled-channel calculations}},
journal = {Phys. Rev. A},
publisher = {American Physical Society},
year = {2020},
volume = {102},
issue = {6},
pages = {062816},
numpages = {9},
note = {experiment & theory},
doi = {https://doi.org/10.1103/PhysRevA.102.062816}
}
|
||||||
| A. Niggas, S. Creutzburg, J. Schwestka, B. Wöckinger, T. Gupta, P.L. Grande, D. Eder, J.P. Marques, B.C. Bayer, F. Aumayr, R. Bennett & R.A. Wilhelm | Peeling graphite layer by layer reveals the charge exchange dynamics of ions inside a solid | 2021 | Commun. Phys. 4, 180 |
|||
| Abstract: {Over seventy years ago, Niels Bohr described how the charge state of an atomic ion moving through a solid changes dynamically as a result of electron capture and loss processes, eventually resulting in an equilibrium charge state. Although obvious, this process has so far eluded direct experimental observation. By peeling a solid, such as graphite, layer by layer, and studying the transmission of highly charged ions through single-, bi- and trilayer graphene, we can now observe dynamical changes in ion charge states with monolayer precision. In addition we present a first-principles approach based on the virtual photon model for interparticle energy transfer to corroborate our findings. Our model that uses a Gaussian shaped dynamic polarisability rather than a spatial delta function is a major step in providing a self-consistent description for interparticle de-excitation processes at the limit of small separations.} | ||||||
BibTeX:
@article{Niggas21,
author = {Niggas, A. and Creutzburg, S. and Schwestka, J. and Wöckinger, B. and Gupta, T. and Grande, P. L. and Eder, D. and Marques, J. P. and Bayer, B. C. and Aumayr, F. and Bennett, R. and Wilhelm, R. A.},
title = {{Peeling graphite layer by layer reveals the charge exchange dynamics of ions inside a solid}},
journal = {Commun. Phys.},
publisher = {Nature Research},
year = {2021},
volume = {4},
pages = {180},
numpages = {9},
note = {experiment & theory},
doi = {https://doi.org/10.1038/s42005-021-00686-1}
}
|
||||||
| A.C. LaForge, R. Michiels, Y. Ovcharenko, A. Ngai, J.M. Escartín, N. Berrah, C. Callegari, A. Clark, M. Coreno, R. Cucini, M. Di Fraia, M. Drabbels, E. Fasshauer, P. Finetti, L. Giannessi, C. Grazioli, D. Iablonskyi, B. Langbehn, T. Nishiyama, V. Oliver, P. Piseri, O. Plekan, K.C. Prince, D. Rupp, S. Stranges, K. Ueda, N. Sisourat, J. Eloranta, M. Pi, M. Barranco, F. Stienkemeier, T. Möller & M. Mudrich | Ultrafast Resonant Interatomic Coulombic Decay Induced by Quantum Fluid Dynamics | 2021 | Phys. Rev. X 11, 021011 |
|||
| Abstract: {Interatomic processes play a crucial role in weakly bound complexes exposed to ionizing radiation; therefore, gaining a thorough understanding of their efficiency is of fundamental importance. Here, we directly measure the timescale of interatomic Coulombic decay (ICD) in resonantly excited helium nanodroplets using a high-resolution, tunable, extreme ultraviolet free-electron laser. Over an extensive range of droplet sizes and laser intensities, we discover the decay to be surprisingly fast, with decay times as short as 400 fs, nearly independent of the density of the excited states. Using a combination of time-dependent density functional theory and ab initio quantum chemistry calculations, we elucidate the mechanisms of this ultrafast decay process, where pairs of excited helium atoms in one droplet strongly attract each other and form merging void bubbles, which drastically accelerates ICD.} | ||||||
BibTeX:
@article{LaForge21,
author = {LaForge, A. C. and Michiels, R. and Ovcharenko, Y. and Ngai, A. and Escartín, J. M. and Berrah, N. and Callegari, C. and Clark, A. and Coreno, M. and Cucini, R. and Di Fraia, M. and Drabbels, M. and Fasshauer, E. and Finetti, P. and Giannessi, L. and Grazioli, C. and Iablonskyi, D. and Langbehn, B. and Nishiyama, T. and Oliver, V. and Piseri, P. and Plekan, O. and Prince, K. C. and Rupp, D. and Stranges, S. and Ueda, K. and Sisourat, N. and Eloranta, J. and Pi, M. and Barranco, M. and Stienkemeier, F. and Möller, T and Mudrich, M.},
title = {{Ultrafast Resonant Interatomic Coulombic Decay Induced by Quantum Fluid Dynamics}},
journal = {Phys. Rev. X},
publisher = {American Physical Society},
year = {2021},
volume = {11},
pages = {021011},
numpages = {11},
note = {experiment & theory},
doi = {https://doi.org/10.1103/PhysRevX.11.021011}
}
|
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| C. Küstner-Wetekam, X.Q. Hu, L. Marder, Ph. Schmidt, C. Ozga, Ch. Zindel, H. Otto, Y.G. Peng, J.G. Wang, C. Richter, N. Sisourat, U. Hergenhahn, A. Knie, A. Ehresmann, Y. Wu & A. Hans | Nature and impact of charge transfer to ground-state dications in atomic and molecular environments | 2021 | Phys. Rev. A 104, 042802 |
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| Abstract: {Charge transfer processes between weakly bound entities play an important role in various chemical and biological environments. In this combined experimental and theoretical work, we investigate the nature of charge-transfer processes in homogeneous atomic and heterogeneous atomic-molecular clusters. Our results reveal fundamentally different processes to be at play in pure argon clusters compared to mixed argon-nitrogen systems: We demonstrate that the former species decay via photon-mediated charge transfer while a nonradiative direct process is found dominant in the atomic-molecular cases. Our results are of general interest for studies on charge redistribution in more complex and biologically relevant samples where molecules are involved.} | ||||||
BibTeX:
@article{Kustner-Wetekam21,
author = {Küstner-Wetekam, C. and Hu, X. Q. and Marder, L. and Schmidt, Ph. and Ozga, C. and Zindel, Ch. and Otto, H. and Peng, Y. G. and Wang, J. G. and Richter, C. and Sisourat, N. and Hergenhahn, U. and Knie, A. and Ehresmann, A. and Wu, Y. and Hans, A.},
title = {{Nature and impact of charge transfer to ground-state dications in atomic and molecular environments}},
journal = {Phys. Rev. A},
publisher = {American Physical Society},
year = {2021},
volume = {104},
issue = {4},
pages = {042802},
numpages = {5},
note = {experiment & theory},
doi = {https://doi.org/10.1103/PhysRevA.104.042802}
}
|
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| A. Hans, Ph. Schmidt, C. Küstner-Wetekam, F. Trinter, S. Deinert, D. Bloß, J.H. Viehmann, R. Schaf, M. Gerstel, C.M. Saak, J. Buck, S. Klumpp, G. Hartmann, L.S. Cederbaum, N.V. Kryzhevoi & A. Knie | Suppression of X-ray-Induced Radiation Damage to Biomolecules in Aqueous Environments by Immediate Intermolecular Decay of Inner-Shell Vacancies | 2021 | J. Phys. Chem. Lett. 12, 7146 |
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| Abstract: {The predominant reason for the damaging power of high-energy radiation is multiple ionization of a molecule, either direct or via the decay of highly excited intermediates, as, e.g., in the case of X-ray irradiation. Consequently, the molecule is irreparably damaged by the subsequent fragmentation in a Coulomb explosion. In an aqueous environment, however, it has been observed that irradiated molecules may be saved from fragmentation presumably by charge and energy dissipation mechanisms. Here, we show that the protective effect of the environment sets in even earlier than hitherto expected, namely immediately after single inner-shell ionization. By combining coincidence measurements of the fragmentation of X-ray-irradiated microsolvated pyrimidine molecules with theoretical calculations, we identify direct intermolecular electronic decay as the protective mechanism, outrunning the usually dominant Auger decay. Our results demonstrate that such processes play a key role in charge delocalization and have to be considered in investigations and models on high-energy radiation damage in realistic environments.} | ||||||
BibTeX:
@article{Hans21,
author = {Hans, A. and Schmidt, Ph. and Küstner-Wetekam, C. and Trinter, F. and Deinert, S. and Bloß, D. and Viehmann, J. H. and Schaf, R. and Gerstel, M. and Saak, C. M. and Buck, J. and Klumpp, S. and Hartmann, G. and Cederbaum, L. S. and Kryzhevoi, N. V. and Knie, A.},
title = {{Suppression of X-ray-Induced Radiation Damage to Biomolecules in Aqueous Environments by Immediate Intermolecular Decay of Inner-Shell Vacancies}},
journal = {J. Phys. Chem. Lett.},
publisher = {American Chemical Society},
year = {2021},
volume = {12},
pages = {7146},
numpages = {5},
note = {experiment & theory},
doi = {https://doi.org/10.1021/acs.jpclett.1c01879}
}
|
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| C. Callegari, A.N. Grum-Grzhimailo, K.L. Ishikawa, K.C. Prince, G. Sansone & K. Ueda | Atomic, molecular and optical physics applications of longitudinally coherent and narrow bandwidth Free-Electron Lasers | 2021 | Phys. Rep. 904, 1 |
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| Abstract: {Short wavelength Free-Electron Lasers (FELs) are among the newest light sources available to scientists to probe a wide range of phenomena, with chemical, physical and biological applications, using soft and hard X-rays. These sources include the currently most powerful hard X-ray light sources in the world and are characterized by extremely high powers and high transverse coherence, but the first FELs had, and many still have, reduced longitudinal coherence. Now it is possible to achieve good longitudinal coherence (narrow bandwidth in the frequency domain) and here we discuss and illustrate a range of experiments utilizing this property, and their underlying physics. The primary applications are those which require high resolution (for example resonant experiments), or temporal coherence (for example coherent control experiments). The currently available light sources extend the vast range of laboratory laser techniques to short wavelengths.} | ||||||
BibTeX:
@article{Callegari21,
author = {Callegari, C. and Grum-Grzhimailo, A. N. and Ishikawa, K. L. and Prince, K. C. and Sansone, G. and Ueda, K.},
title = {{Atomic, molecular and optical physics applications of longitudinally coherent and narrow bandwidth Free-Electron Lasers}},
journal = {Phys. Rep.},
publisher = {Elsevier},
year = {2021},
volume = {904},
pages = {1},
numpages = {59},
note = {experiment & theory},
doi = {https://doi.org/10.1016/j.physrep.2020.12.002}
}
|
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| J. Zhou, S. Jia, A.D. Skitnevskaya, E. Wang, T. Hähnel, E.K. Grigoricheva, X. Xue, J.-X. Li, A.I. Kuleff, A. Dorn & X. Ren | Concerted Double Hydrogen-Bond Breaking by Intermolecular Coulombic Decay in the Formic Acid Dimer | 2022 | J. Phys. Chem. Lett. 13, 4272-4279 |
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| Abstract: {Hydrogen bonds are ubiquitous in nature and of fundamental importance to the chemical and physical properties of molecular systems in the condensed phase. Nevertheless, our understanding of the structural and dynamical properties of hydrogen-bonded complexes in particular in electronic excited states remains very incomplete. Here, by using formic acid (FA) dimer as a prototype of DNA base pair, we investigate the ultrafast decay process initiated by removal of an electron from the inner-valence shell of the molecule upon electron-beam irradiation. Through fragment-ion and electron coincident momentum measurements and ab initio calculations, we find that de-excitation of an outer-valence electron at the same site can initiate ultrafast energy transfer to the neighboring molecule, which is in turn ionized through the emission of low-energy electrons. Our study reveals a concerted breaking of double hydrogen-bond in the dimer initiated by the ultrafast molecular rotations of two FA+ cations following this nonlocal decay mechanism.} | ||||||
BibTeX:
@article{Zhou22,
author = {Zhou, J. and Jia, S. and Skitnevskaya, A. D. and Wang, E. and Hähnel, T. and Grigoricheva, E. K. and Xue, X. and Li, J.-X. and Kuleff, A. I. and Dorn, A. and Ren, X.},
title = {{Concerted Double Hydrogen-Bond Breaking by Intermolecular Coulombic Decay in the Formic Acid Dimer}},
journal = {J. Phys. Chem. Lett.},
year = {2022},
volume = {13},
pages = {4272-4279},
note = {experiment & theory},
doi = {https://doi.org/10.1021/acs.jpclett.2c00957}
}
|
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| J. Zhou, M. Belina, S. Jia, X. Xue, X. Hao, X. Ren & Petr Slavíček | Ultrafast Charge and Proton Transfer in Doubly Ionized Ammonia Dimers | 2022 | J. Phys. Chem. Lett. 13, 10603-10611 |
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| Abstract: {We investigate the ultrafast energy and charge transfer processes between ammonia molecules following ionization reactions initiated by electron impact. Exploring ionization-induced processes in molecular clusters provides us with a detailed insight into the dynamics using experiments in the energy domain. We ionize the ammonia dimer with 200 eV electrons and apply the fragment ions coincident momentum spectroscopy and nonadiabatic molecular dynamics simulations. We identify two mechanisms leading to the doubly charged ammonia dimer. In the first one, a single molecule is ionized. This initiates an ultrafast proton transfer process, leading to the formation of the NH2+ + NH4+ pair. Alternatively, a dimer with a delocalized charge is formed dominantly via the intermolecular Coulombic decay, forming the NH3+·NH3+ dication. This dication further dissociates into two NH3+ cations. The ab initio calculations have reproduced the measured kinetic energy release of the ion pairs and revealed the dynamical processes following the double ionization.} | ||||||
BibTeX:
@article{Zhou22_3,
author = {Zhou, J. and Belina, M. and Jia, S. and Xue, X. and Hao, X. and Ren, X. and Slavíček, Petr},
title = {{Ultrafast Charge and Proton Transfer in Doubly Ionized Ammonia Dimers}},
journal = {J. Phys. Chem. Lett.},
year = {2022},
volume = {13},
pages = {10603-10611},
note = {experiment & theory},
doi = {https://doi.org/10.1021/acs.jpclett.2c02560}
}
|
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| R.A. Wilhelm | The charge exchange of slow highly charged ions at surfaces unraveled with freestanding 2D materials | 2022 | Surf. Sci. Rep. 77, 100577 |
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| Abstract: {The property of a variable charge state makes ions unique to other types of radiation a material surface can be exposed to. As a consequence of charge exchange between ions and surfaces, energy is transferred to the surface and material damage may be triggered. Furthermore, a changing charge state of the ion alters its slowing down process in solids and has important implications when back-scattered ions are to be measured for material analysis purposes. Over the last decades extensive research was devoted to the understanding of ion charge exchange with solids. Here I review recent progress in this field with special emphasize on slow ions in high charge states. This class of ions allows a detailed analysis of charge exchange in experiments, which employ also ultra-thin solid targets and therefore give experimental access to electronic processes on the femtosecond timescale. In this review I will discuss general properties of charge exchange and present typical experimental techniques. I will also discuss current developments in the modelling and simulation of ion-surface interaction. Recent findings using freestanding 2D materials are discussed as well as results from spectroscopy of emitted secondary particles. The paper concludes with a unified picture of ion charge exchange at surfaces and presents possible applications based on the understanding of the underlying physics.} | ||||||
BibTeX:
@article{Wilhelm22,
author = {Wilhelm, R. A.},
title = {{The charge exchange of slow highly charged ions at surfaces unraveled with freestanding 2D materials}},
journal = {Surf. Sci. Rep.},
year = {2022},
volume = {77},
pages = {100577},
note = {experiment & theory},
doi = {https://doi.org/10.1016/j.surfrep.2022.100577}
}
|
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| F. Trinter, T. Miteva, M. Weller, A. Hartung, M. Richter, J.B. Williams, A. Gatton, B. Gaire, J. Sartor, A. Landers, B. Berry, I. Ben-Itzhak, N. Sisourat, V. Stumpf, K. Gokhberg, R. Dörner, T. Jahnke & T. Weber | Ultrafast Temporal Evolution of Interatomic Coulombic Decay in NeKr Dimers | 2022 | Chem. Sci. 13, 1789 |
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| Abstract: {We investigate interatomic Coulombic decay in NeKr dimers after neon inner-valence photoionization [Ne+(2s-1)] using a synchrotron light source. We measure with energy resolution the two singly charged ions of the Coulomb-exploding dimer dication and the photoelectron in coincidence. By carefully tracing the post-collision interaction between the photoelectron and the emitted ICD electron we are able to probe the temporal evolution of the state as it decays. Although the ionizing light pulses are 80 picoseconds long, we determine the lifetime of the intermediate dimer cation state and visualize the contraction of the nuclear structure on the femtosecond time scale.} | ||||||
BibTeX:
@article{Trinter21,
author = {Trinter, F. and Miteva, T. and Weller, M. and Hartung, A. and Richter, M. and Williams, J. B. and Gatton, A. and Gaire, B. and Sartor, J. and Landers, A. and Berry, B. and Ben-Itzhak, I. and Sisourat, N. and Stumpf, V. and Gokhberg, K. and Dörner, R. and Jahnke, T. and Weber, T.},
title = {{Ultrafast Temporal Evolution of Interatomic Coulombic Decay in NeKr Dimers}},
journal = {Chem. Sci.},
publisher = {The Royal Society of Chemistry},
year = {2022},
volume = {13},
issue = {6},
pages = {1789},
note = {experiment & theory},
doi = {https://doi.org/10.1039/D1SC04630F}
}
|
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| H.C. Schewe, E. Muchová, M. Belina, T. Buttersack, D. Stemer, R. Seidel, S. Thürmer, P. Slavíček & B. Winter | Observation of intermolecular Coulombic decay and shake-up satellites in liquid ammonia | 2022 | Struct. Dyn. 9, 044901 |
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| Abstract: {We report the first nitrogen 1s Auger–Meitner electron spectrum from a liquid ammonia microjet at a temperature of ∼223 K (–50°C) and compare it with the simultaneously measured spectrum for gas-phase ammonia. The spectra from both phases are interpreted with the assistance of high-level electronic structure and ab initio molecular dynamics calculations. In addition to the regular Auger–Meitner-electron features, we observe electron emission at kinetic energies of 374–388 eV, above the leading Auger–Meitner peak (3a12). Based on the electronic structure calculations, we assign this peak to a shake-up satellite in the gas phase, i.e., Auger–Meitner emission from an intermediate state with additional valence excitation present. The high-energy contribution is significantly enhanced in the liquid phase. We consider various mechanisms contributing to this feature. First, in analogy with other hydrogen-bonded liquids (noticeably water), the high-energy signal may be a signature for an ultrafast proton transfer taking place before the electronic decay (proton transfer mediated charge separation). The ab initio dynamical calculations show, however, that such a process is much slower than electronic decay and is, thus, very unlikely. Next, we consider a non-local version of the Auger–Meitner decay, the Intermolecular Coulombic Decay. The electronic structure calculations support an important contribution of this purely electronic mechanism. Finally, we discuss a non-local enhancement of the shake-up processes.} | ||||||
BibTeX:
@article{Schewe22,
author = {Schewe, H. C. and Muchová, E. and Belina, M. and Buttersack, T. and Stemer, D. and Seidel, R. and Thürmer, S. and Slavíček, P. and Winter, B.},
title = {{Observation of intermolecular Coulombic decay and shake-up satellites in liquid ammonia}},
journal = {Struct. Dyn.},
year = {2022},
volume = {9},
pages = {044901},
note = {experiment & theory},
doi = {https://doi.org/10.1063/4.0000151}
}
|
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| X. Ren, J. Zhou, E. Wang, T. Yang, Z. Xu, N. Sisourat, T. Pfeifer & A. Dorn | Ultrafast energy transfer between π-stacked aromatic rings upon inner-valence ionization | 2022 | Nat. Chem. 14, 232 |
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| Abstract: {Non-covalently bound aromatic systems are ubiquitous and govern the physicochemical properties of various organic materials. They are important to many phenomena of biological and technological relevance, such as protein folding, base-pair stacking in nucleic acids, molecular recognition and self-assembly, DNA–drug interactions, crystal engineering and organic electronics. Nevertheless, their molecular dynamics and chemical reactivity, particularly in electronic excited states, are not fully understood. Here, we observe intermolecular Coulombic decay in benzene dimers, (C6H6)2–the simplest prototypes of noncovalent π–π interactions between aromatic systems. Intermolecular Coulombic decay is initiated by a carbon 2s vacancy state produced by electron-impact ionization and proceeds through ultrafast energy transfer between the benzene molecules. As a result, the dimer relaxes with the emission of a further low-energy electron (<10 eV) and a pair of C6H6+ cations undergoing Coulomb explosion. Coincident fragment-ion and electron momentum spectroscopy, accompanied by ab initio calculations, enables us to elucidate the dynamical details of this ultrafast relaxation process.} | ||||||
BibTeX:
@article{Ren21,
author = {Ren, X. and Zhou, J. and Wang, E. and Yang, T. and Xu, Z. and Sisourat, N. and Pfeifer, T. and Dorn, A.},
title = {{Ultrafast energy transfer between π-stacked aromatic rings upon inner-valence ionization}},
journal = {Nat. Chem.},
year = {2022},
volume = {14},
issue = {2},
pages = {232},
note = {experiment & theory},
doi = {https://doi.org/10.1038/s41557-021-00838-4}
}
|
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| X. Holzapfel, T. Miteva, N. Sisourat, A. Schrodt, L. Marder, D. Bloß, C. Ozga, C. Küstner-Wetekam, A. Ehresmann, A. Knie & A. Hans | Properties of radiative charge transfer in heterogeneous noble-gas clusters | 2022 | Phys. Rev. A 105, 022815 |
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| Abstract: {Radiative charge transfer (RCT) from cationic to neutral atoms is a fundamental and frequently occurring process in ion-neutral collisions and in van der Waals clusters. In contrast to collisions with only two collision partners, RCT in clusters is more involved as it may depend on the cluster size, the cluster stoichiometry, and the local arrangement of atoms in the cluster. Here, we present a systematic investigation of an RCT photon spectrum as a function of cluster size, stoichometry, and local atom arrangement. For this purpose, we utilize RCT in heterogeneous NeKr and NeXe clusters after Ne 2p photoionization. Our results confirm that Ne dimer ions form prior to RCT if enough Ne is available and we observe that different features dominate the photon spectrum depending on the cluster production parameters. Additionally, we find that the lifetime of the radiative decay is sensitive to the cluster stoichiometry, which we explain and interpret by theoretical calculations on the RCT decay width for different local geometric structures of the involved atoms. We conclude that RCT properties such as photon spectrum and lifetime in turn exhibit information on the mean size and stoichiometry of a cluster jet and the arrangement of the involved atoms..} | ||||||
BibTeX:
@article{Holzapfel22,
author = {Holzapfel, X. and Miteva, T. and Sisourat, N. and Schrodt, A. and Marder, L. and Bloß, D. and Ozga, C. and Küstner-Wetekam, C. and Ehresmann, A. and Knie, A. and Hans, A.},
title = {{Properties of radiative charge transfer in heterogeneous noble-gas clusters}},
journal = {Phys. Rev. A},
publisher = {American Physical Society},
year = {2022},
volume = {105},
issue = {2},
pages = {022815},
numpages = {9},
note = {experiment & theory},
doi = {https://doi.org/10.1103/PhysRevA.105.022815}
}
|
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| G. Gopakumar, E. Muchová, I. Unger, S. Malerz, F. Trinter, G. Öhrwall, F. Lipparini, B. Mennucci, D. Céolin, C. Caleman, I. Wilkinson, B. Winter, P. Slavíček, U. Hergenhahn & O. Björneholm | Probing aqueous ions with non-local Auger relaxation | 2022 | Phys. Chem. Chem. Phys. 24, 8661-8671 |
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| Abstract: {Non-local analogues of Auger decay are increasingly recognized as important relaxation processes in the condensed phase. Here, we explore non-local autoionization, specifically Intermolecular Coulombic Decay (ICD), of a series of aqueous-phase isoelectronic cations following 1s core-level ionization. In particular, we focus on Na+, Mg2+, and Al3+ ions. We unambiguously identify the ICD contribution to the K-edge Auger spectrum. The different strength of the ion–water interactions is manifested by varying intensities of the respective signals: the ICD signal intensity is greatest for the Al3+ case, weaker for Mg2+, and absent for weakly-solvent-bound Na+. With the assistance of ab initio calculations and molecular dynamics simulations, we provide a microscopic understanding of the non-local decay processes. We assign the ICD signals to decay processes ending in two-hole states, delocalized between the central ion and neighbouring water. Importantly, these processes are shown to be highly selective with respect to the promoted water solvent ionization channels. Furthermore, using a core-hole-clock analysis, the associated ICD timescales are estimated to be around 76 fs for Mg2+ and 34 fs for Al3+. Building on these results, we argue that Auger and ICD spectroscopy represents a unique tool for the exploration of intra- and inter-molecular structure in the liquid phase, simultaneously providing both structural and electronic information.} | ||||||
BibTeX:
@article{Gopakumar22,
author = {Gopakumar, G. and Muchová, E. and Unger, I. and Malerz, S. and Trinter, F. and Öhrwall, G. and Lipparini, F. and Mennucci, B. and Céolin, D. and Caleman, C. and Wilkinson, I. and Winter, B. and Slavíček, P. and Hergenhahn, U. and Björneholm, O.},
title = {{Probing aqueous ions with non-local Auger relaxation}},
journal = {Phys. Chem. Chem. Phys.},
publisher = {The Royal Society of Chemistry},
year = {2022},
volume = {24},
issue = {15},
pages = {8661-8671},
note = {experiment & theory},
doi = {https://doi.org/10.1039/D2CP00227B}
}
|
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| S. Barik, S. Dutta, N.R. Behera, R.K. Kushawaha, Y. Sajeev & G. Aravind | Ambient-light-induced intermolecular Coulombic decay in unbound pyridine monomers | 2022 | Nature Chem. 14, 1098-1102 |
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| Abstract: {Intermolecular Coulombic decay (ICD) is a process whereby photoexcited molecules relax by ionizing their neighbouring molecules. ICD is efficient when intermolecular interactions are active and consequently it is observed only in weakly bound systems, such as clusters and hydrogen-bonded systems. Here we report an efficient ICD between unbound molecules excited at ambient-light intensities. On the photoexcitation of gas-phase pyridine monomers, well below the ionization threshold and at low laser intensities, we detected the parent and heavier-than-parent cations. The isotropic emission of slow electrons revealed ICD as the underlying process. π--π* excitation in unbounded pyridine monomers triggered an associative interaction between them, which leads to an efficient three-centre ICD. The cation resulting from the molecular association of the three pyridine centres relaxed through fragmentation. This below-threshold ionization under ambient light has implications for the understanding of radiation damage and astrochemistry.} | ||||||
BibTeX:
@article{Barik22,
author = {Barik, S. and Dutta, S. and Behera, N. R. and Kushawaha, R. K. and Sajeev, Y. and Aravind, G.},
title = {{Ambient-light-induced intermolecular Coulombic decay in unbound pyridine monomers}},
journal = {Nature Chem.},
year = {2022},
volume = {14},
pages = {1098-1102},
note = {experiment & theory},
doi = {https://doi.org/10.1038/s41557-022-01002-2}
}
|
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| J.D. Asmussen, R. Michiels, U. Bangert, N. Sisourat, M. Binz, L. Bruder, M. Danailov, M. Di Fraia, R. Feifel, L. Giannessi, O. Plekan, K.C. Prince, R.J. Squibb, D. Uhl, A. Wituschek, M. Zangrando, C. Callegari, F. Stienkemeier & M. Mudrich | Time-Resolved Ultrafast Interatomic Coulombic Decay in Superexcited Sodium-Doped Helium Nanodroplets | 2022 | J. Phys. Chem. Lett. 13, 4470-4478 |
|||
| Abstract: {The autoionization dynamics of superexcited superfluid He nanodroplets doped with Na atoms is studied by extreme-ultraviolet (XUV) time-resolved electron spectroscopy. Following excitation into the higher-lying droplet absorption band, the droplet relaxes into the lowest metastable atomic 1s2s 1,3S states from which interatomic Coulombic decay (ICD) takes place either between two excited He atoms or between an excited He atom and a Na atom attached to the droplet surface. Four main ICD channels are identified, and their decay times are determined by varying the delay between the XUV pulse and a UV pulse that ionizes the initial excited state and thereby quenches ICD. The decay times for the different channels all fall in the range of ∼1 ps, indicating that the ICD dynamics are mainly determined by the droplet environment. A periodic modulation of the transient ICD signals is tentatively attributed to the oscillation of the bubble forming around the localized He excitation.} | ||||||
BibTeX:
@article{Asmussen22,
author = {Asmussen, J. D. and Michiels, R. and Bangert, U. and Sisourat, N. and Binz, M. and Bruder, L. and Danailov, M. and Di Fraia, M. and Feifel, R. and Giannessi, L. and Plekan, O. and Prince, K. C. and Squibb, R. J. and Uhl, D. and Wituschek, A. and Zangrando, M. and Callegari, C. and Stienkemeier, F. and Mudrich, M.},
title = {{Time-Resolved Ultrafast Interatomic Coulombic Decay in Superexcited Sodium-Doped Helium Nanodroplets}},
journal = {J. Phys. Chem. Lett.},
year = {2022},
volume = {13},
pages = {4470-4478},
note = {experiment & theory},
doi = {https://doi.org/10.1021/acs.jpclett.2c00645}
}
|
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| J. Zhou, S. Jia, X. Hu, E. Wang, X. Xue, Y. Wu, J. Wang, A. Dorn & X. Ren | Intermolecular Charge Transfer Induced Fragmentation of Formic Acid Dimers | 2023 | Phys. Rev. Lett. 130, 233001 |
|||
| Abstract: {We investigate the intermolecular nonradiative charge transfer process in a double hydrogen-bonded formic acid (FA) dimer, initiated by electron-collision induced double ionization of one FA molecule. Through fragment ions and electron coincident momentum measurements and ab initio calculations, we obtain direct evidence that electron transfer from the neighboring FA molecule to fill one of the two vacancies occurs by a potential energy curve crossing of FA++ + FA with FA+ + FA+* curves, forming an electronic excited state of dicationic dimers. This process causes the breaking of two hydrogen bonds and subsequently the cleavage of C--H and C--O covalent bonds in the dimers, which is expected to be a general phenomenon occurring in molecular complexes and can have important implications for radiation damage to biological matter.} | ||||||
BibTeX:
@article{Zhou23,
author = {Zhou, J. and Jia, S. and Hu, X. and Wang, E. and Xue, X. and Wu, Y. and Wang, J. and Dorn, A. and Ren, X.},
title = {{Intermolecular Charge Transfer Induced Fragmentation of Formic Acid Dimers}},
journal = {Phys. Rev. Lett.},
publisher = {American Physical Society},
year = {2023},
volume = {130},
issue = {23},
pages = {233001},
numpages = {7},
note = {experiment & theory},
doi = {https://doi.org/10.1103/PhysRevLett.130.233001}
}
|
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| X. Ren, E. Wang, J. Zhou, S. Jia, X. Wang, X. Xue & A. Dorn | Ultrafast molecular dissociation induced by intermolecular Coulombic decay in water clusters | 2023 | Phys. Rev. A 108, 052814 |
|||
| Abstract: {We report a combined experimental and theoretical study on the fragmentation dynamics following the ultrafast intermolecular Coulombic decay (ICD) in (H2O)6 water clusters upon electron impact ionization. By coincident fragment ions and electron momentum spectroscopy, we show that ICD can be initiated by inner-valence ionization of a water molecule. Our ab initio molecular dynamics simulations show that ICD is followed by proton transfer leading to the formation of the (H2O)3⋅H+⋯OH⋅(H2O)2+ ion-radical complex. We propose a possible dissociative mechanism in which the system further dissociates into a pair of radical ions (H3O+/H5O2+) and neutral species of water and hydrogen peroxide (H2O2). The calculated kinetic energy spectrum of a H3O+/H5O2+ ion pair is in good agreement with experiment. Moreover, the present study of ICD in water provides an underlying production mechanism for the reactive oxygen species of H2O2 which is not considered previously in the radiolysis processes of water.} | ||||||
BibTeX:
@article{Ren23,
author = {Ren, X. and Wang, E. and Zhou, J. and Jia, S. and Wang, X. and Xue, X. and Dorn, A.},
title = {{Ultrafast molecular dissociation induced by intermolecular Coulombic decay in water clusters}},
journal = {Phys. Rev. A},
publisher = {American Physical Society},
year = {2023},
volume = {108},
issue = {5},
pages = {052814},
numpages = {9},
note = {experiment & theory},
doi = {https://doi.org/10.1103/PhysRevA.108.052814}
}
|
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| C. Küstner-Wetekam, L. Marder, D. Bloß, C. Honisch, N. Kiefer, C. Richter, S. Rubik, R. Schaf, C. Zindel, M. Förstel, K. Gokhberg, A. Knie, U. Hergenhahn, A. Ehresmann, P. Kolorenč & A. Hans | Experimental quantification of site-specific efficiency of Interatomic Coulombic Decay after inner shell ionization | 2023 | Commun. Phys. 6, 50 |
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| Abstract: {Interatomic Coulombic Decay (ICD) and related interatomic and intermolecular autoionization mechanisms are ubiquitous decay processes of excited atoms and molecules in an environment. It is commonly accepted that the efficiency of ICD of an ionized atom in a cluster increases with an increasing number of nearest neighbors. Here, we present a method for experimental validation of this assumption by a site-specific and quantitative comparison of ICD and its main competitor, Auger decay, in core-level ionized Kr clusters. Our results are in quantitative agreement with scaled theoretical calculations on Kr2.} | ||||||
BibTeX:
@article{Kuestner-Wetekam23,
author = {Küstner-Wetekam, C. and Marder, L. and Bloß, D. and Honisch, C. and Kiefer, N. and Richter, C. and Rubik, S. and Schaf, R. and Zindel, C. and Förstel, M. and Gokhberg, K. and Knie, A. and Hergenhahn, U. and Ehresmann, A. and Kolorenč, P. and Hans, A.},
title = {{Experimental quantification of site-specific efficiency of Interatomic Coulombic Decay after inner shell ionization}},
journal = {Commun. Phys.},
year = {2023},
volume = {6},
pages = {50},
note = {experiment & theory},
doi = {https://doi.org/10.1038/s42005-023-01166-4}
}
|
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| S. Kundu, H. Hu, X. Li, M. Schaible & T.M. Orlando | Electron scattering with ethane adsorbed on rare gas multilayers: Hole transfer, coulomb decay, and ion dissociation | 2023 | J. Chem. Phys. 158, 124309 |
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| Abstract: {{Positive ion desorption following electron impact dissociative ionization of ethane adsorbed on Ar, Kr, and Xe multilayers has been studied as a function of incident electron energy from threshold to 100 eV. Based on the dependence of ion yields on the identity of the rare gas, it is likely that the majority of ethane molecules undergo indirect ionization following hole transfer from the ionized underlying rare gas. This has also been corroborated by density of states calculations showing the energetic alignment of the outer valence states of ethane and the condensed rare gas ionization energies. Due to the near-resonant nature of charge transfer for single-hole states, the ethane molecular ion is excited to different final ionic states on different rare gases, which leads to differences in ion desorption yields and branching ratios. The quantitative yields increase with increasing ionization energy gap between the rare gas and ethane, in the order Ar > Kr > Xe. The large increase in yields from 25 eV onwards for all rare gases is likely due to the formation and decay of two-hole states on neighboring rare gas and ethane molecules due to interatomic and intermolecular Coulomb decay (ICD) and not electron transfer mediated decay (ETMD). The ICD and ETMD pathways become accessible when the incoming electron has sufficient energy to excite the inner valence ns level of the rare gas to a Rydberg state or ionize it. The experimental findings are supported by calculations of thresholds, density of states for the final configurations of these processes, and coupling strengths for hole transfer between ethane and rare gases. The fragment ion branching ratios vary with energy from threshold to about 35 eV, showing the fragmentation pattern changes with the mode of hole transfer and availability of excess energy. Sigma C–C bonds are more likely to break than C–H bonds in the mid-20 eV range, and this effect is most pronounced for Xe, followed by Kr, and then Ar.}} | ||||||
BibTeX:
@article{Kundu23,
author = {Kundu, S. and Hu, H. and Li, X. and Schaible, M. and Orlando, T. M.},
title = {{{Electron scattering with ethane adsorbed on rare gas multilayers: Hole transfer, coulomb decay, and ion dissociation}}},
journal = {J. Chem. Phys.},
year = {2023},
volume = {158},
pages = {124309},
note = {experiment & theory},
doi = {https://doi.org/10.1063/5.0099594}
}
|
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| S. Hartweg, J. Barnes, B.L. Yoder, G.A. Garcia, L. Nahon, E. Miliordos & R. Signorell | Solvated dielectrons from optical excitation: An effective source of low-energy electrons | 2023 | Science 380, 1161-1165 |
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| Abstract: {Low-energy electrons dissolved in liquid ammonia or aqueous media are powerful reducing agents that promote challenging reduction reactions but can also cause radiation damage to biological tissue. Knowledge of the underlying mechanistic processes remains incomplete, particularly with respect to the details and energetics of the electron transfer steps. In this work, we show how ultraviolet (UV) photoexcitation of metal-ammonia clusters could be used to generate tunable low-energy electrons in situ. Specifically, we identified UV light–induced generation of spin-paired solvated dielectrons and their subsequent relaxation by an unconventional electron transfer–mediated decay as an efficient, low-energy electron source. The process is robust and straightforward to induce with the prospect of improving our understanding of radiation damage and fostering mechanistic studies of solvated electron reduction reactions.} | ||||||
BibTeX:
@article{Hartweg23,
author = {Hartweg, S. and Barnes, J. and Yoder, B. L. and Garcia, G. A. and Nahon, L. and Miliordos, E. and Signorell, R.},
title = {{Solvated dielectrons from optical excitation: An effective source of low-energy electrons}},
journal = {Science},
year = {2023},
volume = {380},
pages = {1161-1165},
note = {experiment & theory},
doi = {https://doi.org/10.1126/science.adh0184}
}
|
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| A. Hans, F. Trinter, P. Schmidt, S. Eckart, S. Grundmann, G. Hartmann, X. Holzapfel, C. Honisch, G. Kastirke, M. Kircher, N. Melzer, C. Ozga, C. Richter, J. Rist, M. Schöffler, D. Trabert, I. Vela-Perez, J.H. Viehmann, M. Weller, R. Dörner, U. Hergenhahn, A. Ehresmann, A. Knie, K. Gokhberg, A. Ghosh & T. Jahnke | Mechanisms of one-photon two-site double ionization after resonant inner-valence excitation in Ne clusters | 2023 | Phys. Rev. Res. 5, 013055 |
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| Abstract: {The role of interatomic and intermolecular energy and charge-transfer processes in weakly bound matter is currently lively debated due to emerging destructive low-energy electrons and radicals. Here, we discuss two mechanisms of single-photon two-site double ionization occurring competitively or subsequently to resonant interatomic Coulombic decay (rICD) in inner-valence (2s → np) excited Ne dimers and clusters. The first mechanism is photoelectron-impact ionization which is, in general, not related to resonant excitation, but in the present case strongly enhanced and, thus, observable due to resonant excitation. Studying this mechanism at its energetic threshold enables addressing a subset of Ne dimers with selected bond lengths. The second mechanism is collisional ionization of energetic Rydberg atoms, which are produced by rICD in Ne clusters and may be ionized by collisions with neutrals on their way through the medium. Both mechanisms are identified by the coincident detection of charged products and, for the case of collisional ionization, confirmed by calculations. These mechanisms produce one more low-energy electron and ion than conventional rICD and, thus, should be considered in the discussion of the biochemical impact of photoinduced rICD processes.} | ||||||
BibTeX:
@article{Hans23,
author = {Hans, A. and Trinter, F. and Schmidt, P. and Eckart, S. and Grundmann, S. and Hartmann, G. and Holzapfel, X. and Honisch, C. and Kastirke, G. and Kircher, M. and Melzer, N. and Ozga, C. and Richter, C. and Rist, J. and Schöffler, M. and Trabert, D. and Vela-Perez, I. and Viehmann, J. H. and Weller, M. and Dörner, R. and Hergenhahn, U. and Ehresmann, A. and Knie, A. and Gokhberg, K. and Ghosh, A. and Jahnke, T.},
title = {{Mechanisms of one-photon two-site double ionization after resonant inner-valence excitation in Ne clusters}},
journal = {Phys. Rev. Res.},
publisher = {American Physical Society},
year = {2023},
volume = {5},
issue = {1},
pages = {013055},
numpages = {10},
note = {experiment & theory},
doi = {https://doi.org/10.1103/PhysRevResearch.5.013055}
}
|
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| M. Han, J. Fedyk, J.-B. Ji, V. Despré, A.I. Kuleff & H.J. Wörner | Observation of Nuclear Wave-Packet Interference in Ultrafast Interatomic Energy Transfer | 2023 | Phys. Rev. Lett. 130, 253202 |
|||
| Abstract: {We report the experimental observation of quantum interference in the nuclear wave-packet dynamics driving ultrafast excitation-energy transfer in argon dimers below the threshold of interatomic Coulombic decay (ICD). Using time-resolved photoion-photoion coincidence spectroscopy and quantum dynamics simulations, we reveal that the electronic relaxation dynamics of the inner-valence 3s hole on one atom leading to a 4s or 4p excitation on the other one is influenced by nuclear quantum dynamics in the initial state, giving rise to a deep, periodic modulation on the kinetic-energy-release (KER) spectra of the coincident Ar+--Ar+ ion pairs. Moreover, the time-resolved KER spectra show characteristic fingerprints of quantum interference effects during the energy-transfer process. Our findings pave the way to elucidating quantum-interference effects in ultrafast charge- and energy-transfer dynamics in more complex systems, such as molecular clusters and solvated molecules.} | ||||||
BibTeX:
@article{Han23,
author = {Han, M. and Fedyk, J. and Ji, J.-B. and Despré, V. and Kuleff, A. I. and Wörner, H. J.},
title = {{Observation of Nuclear Wave-Packet Interference in Ultrafast Interatomic Energy Transfer}},
journal = {Phys. Rev. Lett.},
publisher = {American Physical Society},
year = {2023},
volume = {130},
issue = {25},
pages = {253202},
numpages = {6},
note = {experiment & theory},
doi = {https://doi.org/10.1103/PhysRevLett.130.253202}
}
|
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| G. Gopakumar, I. Unger, P. Slavíček, U. Hergenhahn, G. Öhrwall, S. Malerz, D. Céolin, F. Trinter, B. Winter, I. Wilkinson, C. Caleman, E. Muchová & O. Björneholm | Radiation damage by extensive local water ionization from two-step electron-transfer-mediated decay of solvated ions | 2023 | Nat. Chem. 15, 1408-1414 |
|||
| Abstract: {Biomolecular radiation damage is largely mediated by radicals and low-energy electrons formed by water ionization rather than by direct ionization of biomolecules. It was speculated that such an extensive, localized water ionization can be caused by ultrafast processes following excitation by core-level ionization of hydrated metal ions. In this model, ions relax via a cascade of local Auger--Meitner and, importantly, non-local charge- and energy-transfer processes involving the water environment. Here, we experimentally and theoretically show that, for solvated paradigmatic intermediate-mass Al3+ ions, electronic relaxation involves two sequential solute--solvent electron transfer-mediated decay processes. The electron transfer-mediated decay steps correspond to sequential relaxation from Al5+5to Al3+ accompanied by formation of four ionized water molecules and two low-energy electrons. Such charge multiplication and the generated highly reactive species are expected to initiate cascades of radical reactions.} | ||||||
BibTeX:
@article{Gopakumar23,
author = {Gopakumar, G. and Unger, I. and Slavíček, P. and Hergenhahn, U. and Öhrwall, G. and Malerz, S. and Céolin, D. and Trinter, F. and Winter, B. and Wilkinson, I. and Caleman, C. and Muchová, E. and Björneholm, O.},
title = {{Radiation damage by extensive local water ionization from two-step electron-transfer-mediated decay of solvated ions}},
journal = {Nat. Chem.},
year = {2023},
volume = {15},
pages = {1408-1414},
note = {experiment & theory},
doi = {https://doi.org/10.1038/s41557-023-01302-1}
}
|
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| L. Ben Ltaief, K. Sishodia, S. Mandal, S. De, S.R. Krishnan, C. Medina, N. Pal, R. Richter, T. Fennel & M. Mudrich | Efficient Indirect Interatomic Coulombic Decay Induced by Photoelectron Impact Excitation in Large Pure Helium Nanodroplets | 2023 | Phys. Rev. Lett. 131, 023001 |
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| Abstract: {Ionization of matter by energetic radiation generally causes complex secondary reactions that are hard to decipher. Using large helium nanodroplets irradiated by extreme ultraviolet (XUV) photons, we show that the full chain of processes ensuing primary photoionization can be tracked in detail by means of high-resolution electron spectroscopy. We find that elastic and inelastic scattering of photoelectrons efficiently induces interatomic Coulombic decay (ICD) in the droplets. This type of indirect ICD even becomes the dominant process of electron emission in nearly the entire XUV range in large droplets with radius ≳ 40 nm. Indirect ICD processes induced by electron scattering likely play an important role in other condensed-phase systems exposed to ionizing radiation as well, including biological matter.} | ||||||
BibTeX:
@article{Ltaief23,
author = {Ben Ltaief, L. and Sishodia, K. and Mandal, S. and De, S. and Krishnan, S. R. and Medina, C. and Pal, N. and Richter, R. and Fennel, T. and Mudrich, M.},
title = {{Efficient Indirect Interatomic Coulombic Decay Induced by Photoelectron Impact Excitation in Large Pure Helium Nanodroplets}},
journal = {Phys. Rev. Lett.},
publisher = {American Physical Society},
year = {2023},
volume = {131},
issue = {2},
pages = {023001},
numpages = {7},
note = {experiment & theory},
doi = {https://doi.org/10.1103/PhysRevLett.131.023001}
}
|
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| N.B. Bejoy, R.K. Singh, N.K. Singh, B. Pananghat & G.N. Patwari | Dynamics of Hydrogen Bond Breaking Induced by Outer-Valence Intermolecular Coulombic Decay | 2023 | J. Phys. Chem. Lett. 14, 5718-5726 |
|||
| Abstract: {The photoexcitation of weakly bound complexes can lead to several decay pathways, depending on the nature of the potential energy surfaces. Upon excitation of a chromophore in a weakly bound complex, ionization of its neighbor upon energy transfer can occur due to a unique relaxation process known as intermolecular Coulombic decay (ICD), a phenomenon of renewed focus owing to its relevance in biological systems. Herein, we report the evidence for outer-valence ICD induced by multiphoton excitation by near-ultraviolet radiation of 4.4 eV photons, hitherto unknown in molecular systems. In the binary complexes of 2,6-difluorophenylacetylene with aliphatic amines, a resonant two-photon excitation localized on the 2,6-difluorophenylacetylene chromophore results in the formation of an amine cation following an outer-valence ICD process. The unique trends in experimentally observed translational energy distribution profiles of the amine cations following hydrogen bond dissociation, analyzed with the help of electronic structure and ab initio molecular dynamics calculations, revealed the presence of a delicate interplay of roaming dynamics, methyl-rotor dynamics, and binding energy.} | ||||||
BibTeX:
@article{Bejoy23,
author = {Bejoy, N. B. and Singh, R. K. and Singh, N. K. and Pananghat, B. and Patwari, G. N.},
title = {{Dynamics of Hydrogen Bond Breaking Induced by Outer-Valence Intermolecular Coulombic Decay}},
journal = {J. Phys. Chem. Lett.},
year = {2023},
volume = {14},
pages = {5718-5726},
note = {experiment & theory},
doi = {https://doi.org/10.1021/acs.jpclett.3c01039}
}
|
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| S. Barik, N. Ranjan Behera, S. Dutta, R. Kumar Kushawaha, Y. Sajeev, R.O. Ramabhadran & G. Aravind | Molecular growth of PANH via intermolecular Coulombic decay | 2023 | Science Adv. 9, eadi0230 |
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| Abstract: {Nitrogen-bearing polycyclic aromatic hydrocarbons (PANHs) are ubiquitous in space. They are considered precursors to advanced biomolecules identified in meteorites. However, their chemical evolution into biomolecules in photodestructive astrophysical mediums remains a paradox. Here, we show that light can efficiently initiate the molecular mass growth of PANHs. Ultraviolet-photoexcited quinoline monomers, the smallest PANH, were observed to associate and intermolecular Coulombic decay between the associating monomers formed the cations of quinoline-dimer. Molecular rearrangements in the dimer cation lead to a dominant formation of cations heavier than quinoline. The enrichment of these heavier cations over all the other cations reveals the efficiency of this route for the mass growth of PANHs in space. This mechanism also leads to a highly reactive unsaturated PANH-ring via CH loss, a hitherto unknown channel in any photon-driven process. The occurrence of this efficient pathway toward complex molecules points to a rich chemistry in dense interstellar clouds. Ambient-light is shown to enable the growth of small biomolecules into large biological motifs.} | ||||||
BibTeX:
@article{Barik23,
author = {S. Barik and N. Ranjan Behera and S. Dutta and R. Kumar Kushawaha and Y. Sajeev and R. O. Ramabhadran and G. Aravind },
title = {{Molecular growth of PANH via intermolecular Coulombic decay}},
journal = {Science Adv.},
year = {2023},
volume = {9},
pages = {eadi0230},
note = {experiment & theory},
doi = {https://doi.org/10.1126/sciadv.adi0230}
}
|
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| J. Zhou, Q. Zeng, C. Wang, S. Jia, X. Xue, X. Hao, L. He, D.M. Mootheril, A. Dorn, D. Ding & X. Ren | Structure determination of heteroaromatic thiophene dimers by intermolecular Coulombic decay upon electron-impact ionization | 2024 | Phys. Rev. A 110, 022809 |
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| Abstract: {This paper reports the structure and intermolecular potential energy curve (PEC) of heteroaromatic thiophene dimers obtained using a cold-target recoil-ion momentum spectroscopy reaction microscope. The three-dimensional momenta and kinetic energy release (KER) of the C4H4S+ + C4H4S+ ion pairs are obtained by coincident momentum measurement. The two-body dissociation channel is initiated either by the rapid removal of one outer-valence electron from each thiophene molecule via sequential ionization or by intermolecular Coulombic decay (ICD). Our analysis of the absolute cross sections indicates that the C4H4S+ + C4H4´S+ ion pair is preferentially formed by the ICD process. The measured KER and PEC, accompanied by ab initio molecular dynamics simulations for three different types of conformers, enable us to clarify the minimum energy configuration of thiophene dimers in the gas phase. These results are helpful for our understanding of π-π and σ-π interactions within heteroaromatic ring complexes.} | ||||||
BibTeX:
@article{Zhou24_2,
author = {Zhou, J. and Zeng, Q. and Wang, C. and Jia, S. and Xue, X. and Hao, X. and He, L. and Mootheril, D. M. and Dorn, A. and Ding, D. and Ren, X.},
title = {{Structure determination of heteroaromatic thiophene dimers by intermolecular Coulombic decay upon electron-impact ionization}},
journal = {Phys. Rev. A},
publisher = {American Physical Society},
year = {2024},
volume = {110},
issue = {2},
pages = {022809},
numpages = {7},
note = {experiment & theory},
doi = {https://doi.org/10.1103/PhysRevA.110.022809}
}
|
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| J. Zhou, S. Jia, X. Xue, A.D. Skitnevskaya, E. Wang, X. Wang, X. Hao, Q. Zeng, A.I. Kuleff, A. Dorn & X. Ren | Revealing the Role of N Heteroatoms in Noncovalent Aromatic Interactions by Ultrafast Intermolecular Coulombic Decay | 2024 | J. Phys. Chem. Lett. 15, 1529-1538 |
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| Abstract: { Despite the widely recognized importance of noncovalent interactions involving aromatic rings in many fields, our understanding of the underlying forces and structural patterns, especially the impact of heteroaromaticity, is still incomplete. Here, we investigate the relaxation processes that follow inner-valence ionization in a range of molecular dimers involving various combinations of benzene, pyridine, and pyrimidine, which initiate an ultrafast intermolecular Coulombic decay process. Multiparticle coincidence momentum spectroscopy, combined with ab initio calculations, enables us to explore the principal orientations of these fundamental dimers and, thus, to elucidate the influence of N heteroatoms on the relative preference of the aromatic π-stacking, H-bonding, and CH−π interactions and their dependence on the number of nitrogen atoms in the rings. Our studies reveal a sensitive tool for the structural imaging of molecular complexes and provide a more complete understanding of the effects of N heteroatoms on the noncovalent aromatic interactions at the molecular level. } | ||||||
BibTeX:
@article{Zhou24,
author = {Zhou, J. and Jia, S. and Xue, X. and Skitnevskaya, A. D. and Wang, E. and Wang, X. and Hao, X. and Zeng, Q. and Kuleff, A. I. and Dorn, A. and Ren, X.},
title = {{{Revealing the Role of N Heteroatoms in Noncovalent Aromatic Interactions by Ultrafast Intermolecular Coulombic Decay}}},
journal = {J. Phys. Chem. Lett.},
year = {2024},
volume = {15},
pages = {1529-1538},
note = {experiment & theory},
doi = {https://doi.org/10.1021/acs.jpclett.3c02979}
}
|
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| K. Mudryk, C. Lee, L. Tomaník, S. Malerz, F. Trinter, U. Hergenhahn, D.M. Neumark, P. Slavíček, S. Bradforth & B. Winter | How Does Mg2+(aq) Interact with ATP(aq)? Biomolecular Structure through the Lens of Liquid-Jet Photoemission Spectroscopy | 2024 | J. Am. Chem. Soc. 146, 16062-16075 |
|||
| Abstract: { Liquid-jet photoemission spectroscopy (LJ-PES) allows for a direct probing of electronic structure in aqueous solutions. We show the applicability of the approach to biomolecules in a complex environment, exploring site-specific information on the interaction of adenosine triphosphate in the aqueous phase (ATP(aq)) with magnesium (Mg2+(aq)), highlighting the synergy brought about by the simultaneous analysis of different regions in the photoelectron spectrum. In particular, we demonstrate intermolecular Coulombic decay (ICD) spectroscopy as a new and powerful addition to the arsenal of techniques for biomolecular structure investigation. We apply LJ-PES assisted by electronic-structure calculations to study ATP(aq) solutions with and without dissolved Mg2+. Valence photoelectron data reveal spectral changes in the phosphate and adenine features of ATP(aq) due to interactions with the divalent cation. Chemical shifts in Mg 2p, Mg 2s, P 2p, and P 2s core-level spectra as a function of the Mg2+/ATP concentration ratio are correlated to the formation of [Mg(ATP)2]6-(aq), [MgATP]2-(aq), and [Mg2ATP](aq)) complexes, demonstrating the element sensitivity of the technique to Mg2+–phosphate interactions. The most direct probe of the intermolecular interactions between ATP(aq) and Mg2+(aq) is delivered by the emerging ICD electrons following ionization of Mg 1s electrons. ICD spectra are shown to sensitively probe ligand exchange in the Mg2+–ATP(aq)) coordination environment. In addition, we report and compare P 2s data from ATP(aq) and adenosine mono- and diphosphate (AMP(aq) and ADP(aq), respectively) solutions, probing the electronic structure of the phosphate chain and the local environment of individual phosphate units in ATP(aq). Our results provide a comprehensive view of the electronic structure of ATP(aq) and Mg2+–ATP(aq) complexes relevant to phosphorylation and dephosphorylation reactions that are central to bioenergetics in living organisms. } | ||||||
BibTeX:
@article{Mudryk24,
author = {Mudryk, K. and Lee, C. and Tomaník, L. and Malerz, S. and Trinter, F. and Hergenhahn, U. and Neumark, D. M. and Slavíček, P. and Bradforth, S. and Winter, B.},
title = {{How Does Mg2+(aq) Interact with ATP(aq)? Biomolecular Structure through the Lens of Liquid-Jet Photoemission Spectroscopy}},
journal = {J. Am. Chem. Soc.},
year = {2024},
volume = {146},
pages = {16062-16075},
note = {experiment & theory},
doi = {https://doi.org/10.1021/jacs.4c03174}
}
|
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| S. Dutta, N.R. Behera, S. Barik, R.K. Kushawaha, Y. Sajeev & G. Aravind | Bimolecular photodissociation of interstellar 1-Cyanonaphthalene via Intermolecular Coulombic decay | 2024 | J. Chem. Phys. 161, 124302 |
|||
| Abstract: {Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous in space and govern the interstellar chemistry. The two isomers of cyanonaphthalene (1-CNN and 2-CNN) were the first PAHs to be recently identified in the Taurus Molecular Cloud (TMC-1). Their large abundance is attributed to high photostability with nearly no photofragmentation at photon energies above the ionization potential. Here, we show that at ambient light and at densities akin to dense molecular clouds and the upper atmosphere of planets and moons, 1-CNN could undergo extensive fragmentation through a new mechanism leading to daughter cations. On UV photoexcitation, at a photon energy way below the ionization threshold, 1-CNN monomers form photoexcited dimer units. Intermolecular Coulombic decay between the two photoexcited units of the dimer leads to ionization, and the subsequent molecular rearrangements form new daughter cations. These daughter cations could react further, contributing to rich bottom-up astrochemistry, and could play a pivotal role in developmental astrobiology. Photofragmentation in atmospheric and astrophysical environments is hitherto known to be unimolecular, while the present results point a pathway involving bimolecular photofragmentation.} | ||||||
BibTeX:
@article{Dutta24,
author = {Dutta, S. and Behera, N. R. and Barik, S. and Kushawaha, R. K. and Sajeev, Y. and Aravind, G.},
title = {{{Bimolecular photodissociation of interstellar 1-Cyanonaphthalene via Intermolecular Coulombic decay}}},
journal = {J. Chem. Phys.},
year = {2024},
volume = {161},
pages = {124302},
note = {experiment & theory},
doi = {https://doi.org/10.1063/5.0226386}
}
|
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| B. Bastian, J.D. Asmussen, L. Ben Ltaief, H.B. Pedersen, K. Sishodia, S. De, S.R. Krishnan, C. Medina, N. Pal, R. Richter, N. Sisourat & M. Mudrich | Observation of Interatomic Coulombic Decay Induced by Double Excitation of Helium in Nanodroplets | 2024 | Phys. Rev. Lett. 132, 233001 |
|||
| Abstract: {Interatomic Coulombic decay (ICD) plays a crucial role in weakly bound complexes exposed to intense or high-energy radiation. So far, neutral or ionic atoms or molecules have been prepared in singly excited electron or hole states that can transfer energy to neighboring centers and cause ionization and radiation damage. Here we demonstrate that a doubly excited atom, despite its extremely short lifetime, can decay by ICD; evidenced by high-resolution photoelectron spectra of He nanodroplets excited to the 2s2p+ state. We find that ICD proceeds by relaxation into excited He*He+ atom-pair states, in agreement with calculations. The ability of inducing ICD by resonant excitation far above the single-ionization threshold opens opportunities for controlling radiation damage to a high degree of element specificity and spectral selectivity. } | ||||||
BibTeX:
@article{Bastian24,
author = {Bastian, B. and Asmussen, J. D. and Ltaief, L. Ben and Pedersen, H. B. and Sishodia, K. and De, S. and Krishnan, S. R. and Medina, C. and Pal, N. and Richter, R. and Sisourat, N. and Mudrich, M.},
title = {{Observation of Interatomic Coulombic Decay Induced by Double Excitation of Helium in Nanodroplets}},
journal = {Phys. Rev. Lett.},
publisher = {American Physical Society},
year = {2024},
volume = {132},
issue = {23},
pages = {233001},
numpages = {7},
note = {experiment & theory},
doi = {https://doi.org/10.1103/PhysRevLett.132.233001}
}
|
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| R. Thissen, P. Lablanquie, R.I. Hall, M. Ukai & K. Ito | Photoionization of argon, krypton and xenon clusters in the inner valence shell region | 1998 | Eur. Phys. J. D 4, 335 |
|||
| Abstract: {Photoionization of rare gas clusters in the innervalence shell region has been investigated using threshold photoelectron and photoion spectrometers and synchrotron radiation. Two classes of states are found to play an important role: (A) valence states, correlated to dissociation limits involving an ion with a hole in its innervalence ns shell, (B) Rydberg states correlated to dissociation limits involving an ion with a hole in its outervalence np shell plus an excited neutral atom. In dimers, class A states are 'bright', that is, accessible by photoionization, and serve as an entrance step to form the class B 'dark' states; this character fades as the size of the cluster increases. In the dimer, the 'Mulliken' valence state is found to present a shallow potential well housing a few vibrational levels; it is predissociated by the class B Rydberg states. During the predissociation a remarkable energy transfer process is observed from the excited ion that loses its innershell electron to its neutral partner.} | ||||||
BibTeX:
@article{Thissen98,
author = {Thissen, R. and Lablanquie, P. and Hall, R. I. and Ukai, M. and Ito, K.},
title = {{Photoionization of argon, krypton and xenon clusters in the inner valence shell region}},
journal = {Eur. Phys. J. D},
publisher = {Springer},
year = {1998},
volume = {4},
issue = {3},
pages = {335},
numpages = {8},
note = {experiment},
doi = {https://doi.org/10.1007/s100530050217}
}
|
||||||
| T.D. Thomas, C. Miron, K. Wiesner, P. Morin, T.X. Carroll & L.J. Saethre | Anomalous Natural Linewidth in the 2p Photoelectron Spectrum of SiF4 | 2002 | Phys. Rev. Lett. 89, 223001 |
|||
| Abstract: {The silicon 2p photoelectron spectra for SiH4, SiF4, and SiCl4 have been analyzed to give the natural linewidths of the Si 2p hole states, which reflect the Auger decay rates of the states. For SiH4 the measured width of 38 meV is in approximate agreement with the prediction of the one-center model (32 meV), but that for SiF4 of 79 meV is more than 5 times the value of 14 meV predicted by this model. Approximate theoretical calculations indicate that valence electrons from the fluorine atoms of SiF4 play an important role in the Auger decay via interatomic processes.} | ||||||
BibTeX:
@article{Thomas02,
author = {Thomas, T. D. and Miron, C. and Wiesner, K. and Morin, P. and Carroll, T. X. and Saethre, L. J.},
title = {{Anomalous Natural Linewidth in the 2p Photoelectron Spectrum of SiF4}},
journal = {Phys. Rev. Lett.},
publisher = {American Physical Society},
year = {2002},
volume = {89},
issue = {22},
pages = {223001},
numpages = {4},
note = {experiment},
doi = {https://doi.org/10.1103/PhysRevLett.89.223001}
}
|
||||||
| S. Marburger, O. Kugeler, U. Hergenhahn & T. Möller | Experimental Evidence for Interatomic Coulombic Decay in Ne Clusters | 2003 | Phys. Rev. Lett. 90, 203401 |
|||
| Abstract: {Electron spectra of photoexcited Ne clusters are shown to display a signal at low kinetic energies that is neither present in the Ne monomer nor at photon energies below the inner-valence 2s threshold. These findings are strong evidence for the existence of interatomic Coulombic decays (ICD), a mechanism that was recently predicted theoretically [Phys. Rev. Lett. 79, 4778 (1997)]. In ICD, an inner-valence hole state in a weakly bonded system can undergo ultrafast relaxation due to energy transfer to a neighboring atom, followed by electron emission from this neighboring site.} | ||||||
BibTeX:
@article{Marburger03,
author = {Marburger, S. and Kugeler, O. and Hergenhahn, U. and Möller, T.},
title = {{Experimental Evidence for Interatomic Coulombic Decay in Ne Clusters}},
journal = {Phys. Rev. Lett.},
publisher = {American Physical Society},
year = {2003},
volume = {90},
issue = {20},
pages = {203401},
numpages = {4},
note = {experiment},
doi = {https://doi.org/10.1103/PhysRevLett.90.203401}
}
|
||||||
| G. Öhrwall, M. Tchaplyguine, M. Lundwall, R. Feifel, H. Bergersen, T. Rander, A. Lindblad, J. Schulz, S. Peredkov, S. Barth, S. Marburger, U. Hergenhahn, S. Svensson & O. Björneholm | Femtosecond Interatomic Coulombic Decay in Free Neon Clusters: Large Lifetime Differences between Surface and Bulk | 2004 | Phys. Rev. Lett. 93, 173401 |
|||
| Abstract: {A quantitative determination of 2s vacancy lifetimes in surface and bulk atoms of free Ne clusters has been made. While for free atoms the 2s inner-valence hole has a ps lifetime, it reduces to 6±1 fs for cluster bulk atoms. For surface atoms, the lifetime is on average longer than 30 fs. The lifetime estimate was obtained from fits of high-resolution photoelectron spectra of Ne clusters. The shortening of the lifetime is attributed to the coordination dependent interatomic Coulombic decay, which is extremely sensitive to internuclear distances.} | ||||||
BibTeX:
@article{Ohrwall04,
author = {Öhrwall, G. and Tchaplyguine, M. and Lundwall, M. and Feifel, R. and Bergersen, H. and Rander, T. and Lindblad, A. and Schulz, J. and Peredkov, S. and Barth, S. and Marburger, S. and Hergenhahn, U. and Svensson, S. and Björneholm, O.},
title = {{Femtosecond Interatomic Coulombic Decay in Free Neon Clusters: Large Lifetime Differences between Surface and Bulk}},
journal = {Phys. Rev. Lett.},
publisher = {American Physical Society},
year = {2004},
volume = {93},
issue = {17},
pages = {173401},
numpages = {4},
note = {experiment},
doi = {https://doi.org/10.1103/PhysRevLett.93.173401}
}
|
||||||
| T. Jahnke, A. Czasch, M.S. Schöffler, S. Schössler, A. Knapp, M. Käsz, J. Titze, C. Wimmer, K. Kreidi, R.E. Grisenti, A. Staudte, O. Jagutzki, U. Hergenhahn, H. Schmidt-Böcking & R. Dörner | Experimental Observation of Interatomic Coulombic Decay in Neon Dimers | 2004 | Phys. Rev. Lett. 93, 163401 |
|||
| Abstract: {Recently Cederbaum et al. [Phys. Rev. Lett. 79, 4778 (1997)] predicted a new decay channel of excited atoms and molecules termed interatomic Coulombic decay (ICD). In ICD the deexcitation energy is transferred via virtual photon exchange to a neighboring atom, which releases it by electron emission. We report on an experimental observation of ICD in 2s ionized neon dimers. The process is unambiguously identified by detecting the energy of two Ne1+ fragments and the ICD electron in coincidence, yielding a clean, background free experimental spectral distribution of the ICD electrons.} | ||||||
BibTeX:
@article{Jahnke04,
author = {Jahnke, T. and Czasch, A. and Schöffler, M. S. and Schössler, S. and Knapp, A. and Käsz, M. and Titze, J. and Wimmer, C. and Kreidi, K. and Grisenti, R. E. and Staudte, A. and Jagutzki, O. and Hergenhahn, U. and Schmidt-Böcking, H. and Dörner, R.},
title = {{Experimental Observation of Interatomic Coulombic Decay in Neon Dimers}},
journal = {Phys. Rev. Lett.},
publisher = {American Physical Society},
year = {2004},
volume = {93},
issue = {16},
pages = {163401},
numpages = {4},
note = {experiment},
doi = {https://doi.org/10.1103/PhysRevLett.93.163401}
}
|
||||||
| H. Schmidt-Böcking, M.S. Schöffler, T. Jahnke, A. Czasch, V. Mergel, L. Schmidt, R. Dörner, O. Jagutzki, M. Hattass, Th. Weber, E. Weigold, H.T. Schmidt, R. Schuch, H. Cederquist, Y. Demkov, C. Whelan, A. Godunov & J. Walters | Many-particle fragmentation processes in atomic and molecular physics -- new insight into the world of correlation | 2005 | Nucl. Instrum. Methods Phys. Res. B 233, 3 |
|||
| Abstract: {Correlated many-particle dynamics in Coulombic systems, which is one of the unsolved fundamental problems in AMO-physics, can now be experimentally approached with so far unprecedented completeness and precision. The recent development of the COLTRIMS technique (COLd Target Recoil Ion Momentum Spectroscopy) provides a coincident multi-fragment imaging technique for eV and sub-eV fragment detection. In its completeness it is as powerful as the bubble chamber in high energy physics. In recent benchmark experiments quasi snapshots (duration as short as an attosecond) of the correlated dynamics between electrons and nuclei have been made for atomic and molecular objects. This new imaging technique has opened a powerful observation window into the hidden world of many-particle dynamics.} | ||||||
BibTeX:
@proceedings{SchmidtBoecking05,
author = {Schmidt-Böcking, H. and Schöffler, M. S. and Jahnke, T. and Czasch, A. and Mergel, V. and Schmidt, L. and Dörner, R. and Jagutzki, O. and Hattass, M. and Weber, Th. and Weigold, E. and Schmidt, H. T. and Schuch, R. and Cederquist, H. and Demkov, Y. and Whelan, C. and Godunov, A. and Walters, J.},
title = {{Many-particle fragmentation processes in atomic and molecular physics -- new insight into the world of correlation}},
journal = {Nucl. Instrum. Methods Phys. Res. B},
series= {8th Workshop on Fast Ion-Atom Collisions},
publisher = {Elsevier},
year = {2005},
volume = {233},
issue = {1--4},
pages = {3},
numpages = {9},
note = {experiment},
doi = {https://doi.org/10.1016/j.nimb.2005.03.079}
}
|
||||||
| A. Czasch, L. Ph.H. Schmidt, T. Jahnke, Th. Weber, O. Jagutzki, S. Schössler, M.S. Schöffler, R. Dörner & H. Schmidt-Böcking | Photo induced multiple fragmentation of atoms and molecules: Dynamics of Coulombic many-particle systems studied with the COLTRIMS reaction microscope | 2005 | Phys. Lett. A 347, 95 |
|||
| Abstract: {Many-particle dynamics in atomic and molecular physics has been investigated by using the COLTRIMS reaction microscope. The COLTRIMS technique visualizes photon and ion induced many-particle fragmentation processes in the eV and milli-eV regime. It reveals the complete momentum pattern in atomic and molecular many-particle reactions comparable to the bubble chamber in nuclear physics.} | ||||||
BibTeX:
@article{Czasch05,
author = {Czasch, A. and Schmidt, L.Ph.H. and Jahnke, T. and Weber, Th. and Jagutzki, O. and Schössler, S. and Schöffler, M. S. and Dörner, R. and Schmidt-Böcking, H.},
title = {{Photo induced multiple fragmentation of atoms and molecules: Dynamics of Coulombic many-particle systems studied with the COLTRIMS reaction microscope}},
journal = {Phys. Lett. A},
publisher = {Elsevier},
year = {2005},
volume = {347},
issue = {1--3},
pages = {95},
numpages = {8},
note = {experiment},
doi = {https://doi.org/10.1016/j.physleta.2005.08.043}
}
|
||||||
| I.L. Bradeanu, R. Flesch, M. Meyer, H.-W. Jochims & E. Rühl | Radiative relaxation in 2p-excited argon clusters: Evidence for the interatomic Coulombic decay mechanism | 2005 | Eur. Phys. J. D 36, 173 |
|||
| Abstract: {The emission of ultraviolet fluorescence radiation from variable size argon clusters is investigated with high spectral resolution in the Ar 2p-excitation regime. The fluorescence excitation spectra reveal strong fluorescence intensity in the Ar 2p-continuum, but no evidence for the occurrence of discrete low-lying core-exciton states in the near-edge regime. This finding is different from the absorption and photoionization cross section of argon clusters and the solid. The dispersed fluorescence shows a broad molecular band centered near 280 nm. The present work indicates that double and triple ionization via the LMM-Auger decay are required to initiate the fluorescence processes in the Ar 2p-continuum. The present results are consistent with the formation of singly charged, excited moieties within the clusters, which are assigned as sources of the radiative emission in the 280 nm regime. A fast energy transfer process (interatomic Coulombic decay (ICD)), which has been proposed by recent theoretical work, is assigned to be primarily the origin of these singly charged, excited cations besides intra-cluster electron impact ionization by the Auger electrons. Our findings give first possible experimental evidence for ICD in the core level regime.} | ||||||
BibTeX:
@article{Bradeanu05,
author = {Bradeanu, I. L. and Flesch, R. and Meyer, M. and Jochims, H.-W. and Rühl, E.},
title = {{Radiative relaxation in 2p-excited argon clusters: Evidence for the interatomic Coulombic decay mechanism}},
journal = {Eur. Phys. J. D},
publisher = {Springer},
year = {2005},
volume = {36},
issue = {2},
pages = {173},
numpages = {6},
note = {experiment},
doi = {https://doi.org/10.1140/epjd/e2005-00223-5}
}
|
||||||
| S. Barth, S. Joshi, S. Marburger, V. Ulrich, A. Lindblad, G. Öhrwall, O. Björneholm & U. Hergenhahn | Observation of resonant Interatomic Coulombic Decay in Ne clusters | 2005 | J. Chem. Phys. 122, 241102 |
|||
| Abstract: {We have measured the electron spectra of Ne clusters after excitation with photon energies around the 2s inner valence threshold. At two photon energies below threshold, a resonantly enhanced surplus of low kinetic-energy electrons is observed. The kinetic energy of the peak does not vary with the photon energy and is slightly larger than the transition energy of Interatomic Coulombic Decay (ICD) above threshold. This leads us to assume that an ICD-like process is present. In analogy to the Auger and the resonant Auger decay this new phenomenon is termed resonant ICD.} | ||||||
BibTeX:
@article{Barth05,
author = {Barth, S. and Joshi, S. and Marburger, S. and Ulrich, V. and Lindblad, A. and Öhrwall, G. and Björneholm, O. and Hergenhahn, U.},
title = {{Observation of resonant Interatomic Coulombic Decay in Ne clusters}},
journal = {J. Chem. Phys.},
publisher = {AIP},
year = {2005},
volume = {122},
issue = {24},
pages = {241102},
numpages = {4},
note = {experiment},
doi = {https://doi.org/10.1063/1.1937395}
}
|
||||||
| Y. Morishita, X.-J. Liu, N. Saito, T. Lischke, M. Kato, G. Prümper, M. Oura, H. Yamaoka, Y. Tamenori, I.H. Suzuki & K. Ueda | Experimental Evidence of Interatomic Coulombic Decay from the Auger Final States in Argon Dimers | 2006 | Phys. Rev. Lett. 96, 243402 |
|||
| Abstract: {Interatomic Coulombic decay (ICD) from an Auger-final dicationic state is observed in the Ar dimer. A 2p inner-shell vacancy created by photoionization is replaced with 3s and 3p vacancies via intra-atomic Auger decay. The Auger-final dicationic state is subject to ICD in which one of the 3p electrons in the same Ar atom fills the 3s vacancy while one of the 3p electrons from the neighboring Ar atom is emitted as an ICD electron. This ICD process is unambiguously identified by electron-ion-ion coincidence spectroscopy in which the kinetic energy of the ICD electron and the kinetic energy release between Ar+ and Ar2+ are measured in coincidence.} | ||||||
BibTeX:
@article{Morishita06,
author = {Morishita, Y. and Liu, X.-J. and Saito, N. and Lischke, T. and Kato, M. and Prümper, G. and Oura, M. and Yamaoka, H. and Tamenori, Y. and Suzuki, I. H. and Ueda, K.},
title = {{Experimental Evidence of Interatomic Coulombic Decay from the Auger Final States in Argon Dimers}},
journal = {Phys. Rev. Lett.},
publisher = {American Physical Society},
year = {2006},
volume = {96},
issue = {24},
pages = {243402},
numpages = {4},
note = {experiment},
doi = {https://doi.org/10.1103/PhysRevLett.96.243402}
}
|
||||||
| S. Barth, S. Marburger, O. Kugeler, V. Ulrich, S. Joshi, A.M. Bradshaw & U. Hergenhahn | The efficiency of Interatomic Coulombic Decay in Ne clusters | 2006 | Chem. Phys. 329, 246 |
|||
| Abstract: {In this article, we demonstrate that Interatomic Coulombic Decay (ICD) is the dominant relaxation channel of Ne 2s inner valence vacancies in free Ne clusters, with an efficiency close to 100%. ICD designates a novel autoionization process of a vacancy in a weakly bonded atomic or molecular cluster. Its main characteristic is the release of an electron from a site different than the original vacancy, which is mediated by ultrafast energy transfer. Results are shown for cluster sizes between approx. 50-600 atoms. A trend towards apparently increased efficiency for larger clusters may result from inelastic scattering processes inside the cluster.} | ||||||
BibTeX:
@article{Barth06_2,
author = {Barth, S. and Marburger, S. and Kugeler, O. and Ulrich, V. and Joshi, S. and Bradshaw, A. M. and Hergenhahn, U.},
title = {{The efficiency of Interatomic Coulombic Decay in Ne clusters}},
journal = {Chem. Phys.},
publisher = {Elsevier},
year = {2006},
volume = {329},
issue = {1--3},
pages = {246},
numpages = {5},
note = {experiment},
doi = {https://doi.org/10.1016/j.chemphys.2006.06.035}
}
|
||||||
| S. Barth, S. Marburger, S. Joshi, V. Ulrich, O. Kugeler & U. Hergenhahn | Interface identification by non-local autoionization transitions | 2006 | Phys. Chem. Chem. Phys. 8, 3218 |
|||
| Abstract: {We use an autoionization process that involves ultrafast energy transfer to neighbouring sites to characterize the formation of NeAr van der Waals bonds in clusters formed by a coexpansion of both gases. This autoionization process, the so-called interatomic or intermolecular coulombic decay (ICD), is ubiquitous in weakly bonded systems. The energy of the electron being emitted in the ICD process is shown to be characteristic of the two neighbouring entities and is therefore suggested as a new means for structural investigation, such as interface identification, of weakly bonded complexes.} | ||||||
BibTeX:
@article{Barth06_1,
author = {Barth, S. and Marburger, S. and Joshi, S. and Ulrich, V. and Kugeler, O. and Hergenhahn, U.},
title = {{Interface identification by non-local autoionization transitions}},
journal = {Phys. Chem. Chem. Phys.},
publisher = {RSC},
year = {2006},
volume = {8},
issue = {27},
pages = {3218},
numpages = {5},
note = {experiment},
doi = {https://doi.org/10.1039/b602019d}
}
|
||||||
| T. Aoto, K. Ito, Y. Hikosaka, E. Shigemasa, F. Penent & P. Lablanquie | Properties of Resonant Interatomic Coulombic Decay in Ne Dimers | 2006 | Phys. Rev. Lett. 97, 243401 |
|||
| Abstract: {Properties of the interatomic Coulombic decay (ICD) process in Ne dimers have been obtained by tracking the formation of energetic Ne+ ions. The double photoionization cross section, deduced from the Ne+/Ne+ coincidence signal, is dominated by the ICD process and presents a threshold 280 meV below the atomic Ne+2s-1 threshold. Rydberg excitation of a 2s electron in the dimer creates molecular Rydberg states whose Σ and Π symmetries have been resolved. These excited states decay by a resonant ICD process releasing an energetic Ne+ ion and a neutral excited Ne* fragment. Subsequent autoionization of the Ne* fragment explains a double photoionization threshold below the dimer 2s ionization threshold.} | ||||||
BibTeX:
@article{Aoto06,
author = {Aoto, T. and Ito, K. and Hikosaka, Y. and Shigemasa, E. and Penent, F. and Lablanquie, P.},
title = {{Properties of Resonant Interatomic Coulombic Decay in Ne Dimers}},
journal = {Phys. Rev. Lett.},
publisher = {American Physical Society},
year = {2006},
volume = {97},
issue = {24},
pages = {243401},
numpages = {4},
note = {experiment},
doi = {https://doi.org/10.1103/PhysRevLett.97.243401}
}
|
||||||
| K. Ueda, X.-J. Liu, G. Prümper, H. Fukuzawa, Y. Morishita & N. Saito | Electron-ion coincidence momentum spectroscopy: Its application to Ar dimer interatomic decay | 2007 | J. Electron Spectrosc. Relat. Phenom. 155, 113 |
|||
| Abstract: {Electron-ion-ion coincidence momentum spectroscopy, a well-established tool to study the molecular-frame core-level photoelectron angular distribution, has been applied to investigate interatomic electronic decay processes in argon dimers Ar2 after the creation of a 2p inner-shell vacancy. Some interatomic Coulombic decay (ICD) processes from an Auger-final dicationic state are identified from the coincidence measurement between the kinetic energy of the ICD electron and the kinetic energy release between Ar+ and Ar2+. The interatomic character of the dissociation processes into Ar+-Ar+ is also discussed.} | ||||||
BibTeX:
@proceedings{Ueda07,
author = {Ueda, K. and Liu, X.-J. and Prümper, G. and Fukuzawa, H. and Morishita, Y. and Saito, N.},
title = {{Electron-ion coincidence momentum spectroscopy: Its application to Ar dimer interatomic decay}},
journal = {J. Electron Spectrosc. Relat. Phenom.},
series= {Scattering, Coincidence and Absorption Studies of Molecules: SCASM2006},
publisher = {Elsevier},
year = {2007},
volume = {155},
issue = {1--3},
pages = {113},
numpages = {6},
note = {experiment},
doi = {https://doi.org/10.1016/j.elspec.2006.10.007}
}
|
||||||
| N. Saito, X.-J. Liu, Y. Morishita, I.H. Suzuki & K. Ueda | Electron-ion multiple coincidence spectroscopy for small molecules and clusters | 2007 | J. Electron Spectrosc. Relat. Phenom. 156--158, 68 |
|||
| Abstract: {We have developed an electron-ion multiple coincidence technique at BL27SU at SPring-8 in Japan, which consists of electron and ion time-of-flight analyzers with multi-hit two-dimensional position sensitive detectors and a supersonic jet from a cooled nozzle. Recent studies on the electron-ion multiple coincidence experiments using this apparatus are reviewed in this paper. We discuss N 1s photoelectron angular distributions in the molecular frame for NO using a new projection analysis method. As an example of de-excitation processes, we have observed interatomic Coulombic decay (ICD) from an Auger-final dicationic state with 3s and 3p holes in the Ar trimer. This ICD process is unambiguously identified by the electron-ion-ion-ion coincidence technique in which the kinetic energy of the ICD electron and the kinetic energy release in the three Ar+ fragmentation are measured in coincidence.} | ||||||
BibTeX:
@proceedings{Saito07_2,
author = {Saito, N. and Liu, X.-J. and Morishita, Y. and Suzuki, I. H. and Ueda, K.},
title = {{Electron-ion multiple coincidence spectroscopy for small molecules and clusters}},
journal = {J. Electron Spectrosc. Relat. Phenom.},
series= {the 10th International Conference on Electronic Spectroscopy and Structure: ICESS-10},
publisher = {Elsevier},
year = {2007},
volume = {156--158},
pages = {68},
numpages = {5},
note = {experiment},
doi = {https://doi.org/10.1016/j.elspec.2006.11.048}
}
|
||||||
| T. Rander, J. Schulz, M. Huttula, A. Mäkinen, M. Tchaplyguine, S. Svensson, G. Öhrwall, O. Björneholm, S. Aksela & H. Aksela | Core-level electron spectroscopy on the sodium dimer Na 2p level | 2007 | Phys. Rev. A 75, 032510 |
|||
| Abstract: {The lifetime broadening and molecular field splitting of the sodium dimer 2p core level is studied by x-ray photoelectron spectroscopy and by Auger electron spectroscopy. The lifetime of the Na 2p core hole has been determined to be 15±8 fs, much shorter than what has previously been reported for solid sodium. The molecular field splitting of this core level has been determined to be 42±10 meV. The Auger measurements have experimentally confirmed that the sodium dimer is a good example of when the Coulomb explosion mechanism determines the spectral shape.} | ||||||
BibTeX:
@article{Rander07,
author = {Rander, T. and Schulz, J. and Huttula, M. and Mäkinen, A. and Tchaplyguine, M. and Svensson, S. and Öhrwall, G. and Björneholm, O. and Aksela, S. and Aksela, H.},
title = {{Core-level electron spectroscopy on the sodium dimer Na 2p level}},
journal = {Phys. Rev. A},
publisher = {American Physical Society},
year = {2007},
volume = {75},
issue = {3},
pages = {032510},
numpages = {4},
note = {experiment},
doi = {https://doi.org/10.1103/PhysRevA.75.032510}
}
|
||||||
| M. Lundwall, W. Pokapanich, H. Bergersen, A. Lindblad, T. Rander, G. Öhrwall, M. Tchaplyguine, S. Barth, U. Hergenhahn, S. Svensson & O. Björneholm | Self-assembled heterogeneous argon/neon core-shell clusters studied by photoelectron spectroscopy | 2007 | J. Chem. Phys. 126, 214706 |
|||
| Abstract: {Clusters formed by a coexpansion process of argon and neon have been studied using synchrotron radiation. Electrons from interatomic Coulombic decay as well as ultraviolet and x-ray photoelectron spectroscopy were used to determine the heterogeneous nature of the clusters and the cluster structure. Binary clusters of argon and neon produced by coexpansion are shown to exhibit a core-shell structure placing argon in the core and neon in the outer shells. Furthermore, the authors show that 2 ML of neon on the argon core is sufficient for neon valence band formation resembling the neon solid. For 1 ML of neon the authors observe a bandwidth narrowing to about half of the bulk value.} | ||||||
BibTeX:
@article{Lundwall07,
author = {Lundwall, M. and Pokapanich, W. and Bergersen, H. and Lindblad, A. and Rander, T. and Öhrwall, G. and Tchaplyguine, M. and Barth, S. and Hergenhahn, U. and Svensson, S. and Björneholm, O.},
title = {{Self-assembled heterogeneous argon/neon core-shell clusters studied by photoelectron spectroscopy}},
journal = {J. Chem. Phys.},
publisher = {AIP},
year = {2007},
volume = {126},
issue = {21},
pages = {214706},
numpages = {8},
note = {experiment},
doi = {https://doi.org/10.1063/1.2735607}
}
|
||||||
| P. Lablanquie, T. Aoto, Y. Hikosaka, Y. Morioka, F. Penent & K. Ito | Appearance of interatomic Coulombic decay in Ar, Kr, and Xe homonuclear dimers | 2007 | J. Chem. Phys. 127, 154323 |
|||
| Abstract: {Interatomic Coulombic decay (ICD) is observed in the rare gas homonuclear dimers Ar2, Kr2, and Xe2 with photoion spectroscopy techniques. Inner valence ionization of the outer ns shell of these systems is known to create a metastable state that dissociates to form a ground state ion and a neutral excited fragment. Inner valence ionization to form ns satellite states leads to similar dissociations, but the neutral fragment gets all the more excited as the internal energy of the ns satellite state increases. When enough excitation energy is transferred to reach the ionization potential, ICD occurs. ICD threshold is observed to coincide with the position of the A+A+ ground state in the Franck-Condon region.} | ||||||
BibTeX:
@article{Lablanquie07,
author = {Lablanquie, P. and Aoto, T. and Hikosaka, Y. and Morioka, Y. and Penent, F. and Ito, K.},
title = {{Appearance of interatomic Coulombic decay in Ar, Kr, and Xe homonuclear dimers}},
journal = {J. Chem. Phys.},
publisher = {AIP},
year = {2007},
volume = {127},
issue = {15},
pages = {154323},
numpages = {9},
note = {experiment},
doi = {https://doi.org/10.1063/1.2778430}
}
|
||||||
| T. Jahnke, A. Czasch, M. Schöffler, S. Schössler, M. Käsz, J. Titze, K. Kreidi, R.E. Grisenti, A. Staudte, O. Jagutzki, L. Ph.H. Schmidt, Th. Weber, H. Schmidt-Böcking, K. Ueda & R. Dörner | Experimental Separation of Virtual Photon Exchange and Electron Transfer in Interatomic Coulombic Decay of Neon Dimers | 2007 | Phys. Rev. Lett. 99, 153401 |
|||
| Abstract: {We investigate the interatomic Coulombic decay (ICD) of neon dimers following photoionization with simultaneous excitation of the ionized atom (shakeup) in a multiparticle coincidence experiment. We find that, depending on the parity of the excited state, which determines whether ICD takes place via virtual dipole photon emission or overlap of the wave functions, the decay happens at different internuclear distances, illustrating that nuclear dynamics heavily influence the electronic decay in the neon dimer.} | ||||||
BibTeX:
@article{Jahnke07_2,
author = {Jahnke, T. and Czasch, A. and Schöffler, M. and Schössler, S. and Käsz, M. and Titze, J. and Kreidi, K. and Grisenti, R. E. and Staudte, A. and Jagutzki, O. and Schmidt, L.Ph.H. and Weber, Th. and Schmidt-Böcking, H. and Ueda, K. and Dörner, R.},
title = {{Experimental Separation of Virtual Photon Exchange and Electron Transfer in Interatomic Coulombic Decay of Neon Dimers}},
journal = {Phys. Rev. Lett.},
publisher = {American Physical Society},
year = {2007},
volume = {99},
issue = {15},
pages = {153401},
numpages = {4},
note = {experiment},
doi = {https://doi.org/10.1103/PhysRevLett.99.153401}
}
|
||||||
| T. Jahnke, A. Czasch, M. Schöffler, S. Schössler, M. Käsz, J. Titze, K. Kreidi, R.E. Grisenti, A. Staudte, O. Jagutzki, L. Ph.H. Schmidt, S.K. Semenov, N.A. Cherepkov, H. Schmidt-Böcking & R. Dörner | Photoelectron and ICD electron angular distributions from fixed-in-space neon dimers | 2007 | J. Phys. B: At. Mol. Opt. Phys. 40, 2597 |
|||
| Abstract: {We report on molecular frame angular distributions of 2s photoelectrons and electrons emitted by interatomic Coulombic decay from neon dimers. We found that the measured angular distribution of the photoelectron strongly depends on the environment of the cluster. The experimental results are in excellent agreement with frozen core Hartree-Fock calculations. The ICD electrons show slight variations in their angular distribution for different kinetic energies.} | ||||||
BibTeX:
@article{Jahnke07_1,
author = {Jahnke, T. and Czasch, A. and Schöffler, M. and Schössler, S. and Käsz, M. and Titze, J. and Kreidi, K. and Grisenti, R. E. and Staudte, A. and Jagutzki, O. and Schmidt, L.Ph.H. and Semenov, S. K. and Cherepkov, N. A. and Schmidt-Böcking, H. and Dörner, R.},
title = {{Photoelectron and ICD electron angular distributions from fixed-in-space neon dimers}},
journal = {J. Phys. B: At. Mol. Opt. Phys.},
publisher = {IOP},
year = {2007},
volume = {40},
issue = {13},
pages = {2597},
numpages = {10},
note = {experiment},
doi = {https://doi.org/10.1088/0953-4075/40/13/006}
}
|
||||||
| T. Gejo, M. Iseda, T. Tamura, K. Honma, J.R. Harries & Y. Tamenori | Investigation of the 2p ionization threshold region of Ar clusters by observation of the fluorescence lifetime | 2007 | J. Electron Spectrosc. Relat. Phenom. 155, 119 |
|||
| Abstract: {Time-resolved soft X-ray and vacuum ultraviolet fluorescence resulting from the decay processes of 2p inner-shell excited Ar clusters has been observed. Fluorescence with 3-10 ns lifetime is observed, and assigned as being cluster-specific. This fluorescence can be attributed to arising from the decay of excited states of either neutral or singly ionized atoms produced via energy transfer or electron transfer processes including the interatomic Coulombic decay mechanism. The time-uncorrelated neutral yield spectra arise from large Ar clusters.} | ||||||
BibTeX:
@proceedings{Gejo07,
author = {Gejo, T. and Iseda, M. and Tamura, T. and Honma, K. and Harries, J. R. and Tamenori, Y.},
title = {{Investigation of the 2p ionization threshold region of Ar clusters by observation of the fluorescence lifetime}},
journal = {J. Electron Spectrosc. Relat. Phenom.},
series= {Scattering, Coincidence and Absorption Studies of Molecules: SCASM2006},
publisher = {Elsevier},
year = {2007},
volume = {155},
issue = {1--3},
pages = {119},
numpages = {5},
note = {experiment},
doi = {https://doi.org/10.1016/j.elspec.2006.11.011}
}
|
||||||
| M. Yamazaki, J. Adachi, Y. Kimura, A. Yagishita, M. Stener, P. Decleva, N. Kosugi, H. Iwayama, K. Nagaya & M. Yao | Decay Channel Dependence of the Photoelectron Angular Distributions in Core-Level Ionization of Ne Dimers | 2008 | Phys. Rev. Lett. 101, 043004 |
|||
| Abstract: {For K-shell photoionization of neon dimers, we report Ne 1s photoelectron angular distributions for Ne2++Ne+ and Ne++Ne+ channels exhibiting quite different patterns. Noninversion-symmetric patterns of the former obtained by the fast interatomic Coulombic decay of Auger final states show direct evidence of core-hole localization. Dipolar patterns of the latter obtained by the slow radiative decay of the other Auger final states clearly show that the radiative process is slow enough to allow dicationic dimers to rotate many times before fragmentation.} | ||||||
BibTeX:
@article{Yamazaki08,
author = {Yamazaki, M. and Adachi, J. and Kimura, Y. and Yagishita, A. and Stener, M. and Decleva, P. and Kosugi, N. and Iwayama, H. and Nagaya, K. and Yao, M.},
title = {{Decay Channel Dependence of the Photoelectron Angular Distributions in Core-Level Ionization of Ne Dimers}},
journal = {Phys. Rev. Lett.},
publisher = {American Physical Society},
year = {2008},
volume = {101},
issue = {4},
pages = {043004},
numpages = {4},
note = {experiment},
doi = {https://doi.org/10.1103/PhysRevLett.101.043004}
}
|
||||||
| K. Ueda, H. Fukuzawa, X.-J. Liu, K. Sakai, G. Prümper, Y. Morishita, N. Saito, I.H. Suzuki, K. Nagaya, H. Iwayama, M. Yao, K. Kreidi, M. Schöffler, T. Jahnke, S. Schössler, R. Dörner, Th. Weber, J. Harries & Y. Tamenori | Interatomic Coulombic decay following the Auger decay: Experimental evidence in rare-gas dimers | 2008 | J. Electron Spectrosc. Relat. Phenom. 166-167, 3 |
|||
| Abstract: {Interatomic Coulombic decay (ICD) in Ar2, ArKr and Kr2 following Ar 2p or Kr 3d Auger decay has been investigated by means of momentum-resolved electron-ion-ion coincidence spectroscopy. This sequential decay leads to Coulombic dissociation into dication and monocation. Simultaneously determining the kinetic energy of the ICD electron and the kinetic energy release between the two atomic ions, we have been able to unambiguously identify the ICD channels. We find that, in general, spin-conserved ICD, in which the singlet (triplet) dicationic state produced via the atomic Auger decay preferentially decays to the singlet (triplet) state, transferring the energy to the other atom, is faster than spin-flip ICD, in which the Auger final singlet (triplet) dicationic state decays to the triplet (singlet) state. However, spin-flip ICD may take place when spin-conserved ICD becomes energetically forbidden. Dipole-forbidden ICDs from Kr2+(4s-2 1S) - B (B = Ar or Kr) to Kr2+(4p-2 1D, 3P) - B+ are also observed.} | ||||||
BibTeX:
@proceedings{Ueda08_2,
author = {Ueda, K. and Fukuzawa, H. and Liu, X.-J. and Sakai, K. and Prümper, G. and Morishita, Y. and Saito, N. and Suzuki, I. H. and Nagaya, K. and Iwayama, H. and Yao, M. and Kreidi, K. and Schöffler, M. and Jahnke, T. and Schössler, S. and Dörner, R. and Weber, Th. and Harries, J. and Tamenori, Y.},
title = {{Interatomic Coulombic decay following the Auger decay: Experimental evidence in rare-gas dimers}},
journal = {J. Electron Spectrosc. Relat. Phenom.},
series= {52nd IUVSTA Workshop on Structure and Dynamics of Free and Supported Nanoparticles using Short-Wavelength Radiation},
publisher = {Elsevier},
year = {2008},
volume = {166-167},
pages = {3},
numpages = {8},
note = {experiment},
doi = {https://doi.org/10.1016/j.elspec.2008.03.002}
}
|
||||||
| K. Ueda | Photoemission and coincidence studies on gas-phase molecules | 2008 | Appl. Phys. A 92, 487 |
|||
| Abstract: {This article describes Young's double-slit experiment using high-energy core-level photoemission from N2 molecules and experimental identification of interatomic Coulombic decay in Ar2 dimers after Auger decay using k-resolved electron-ion-ion coincidence spectroscopy, aiming to illustrate the leading edge of gas-phase experiments using synchrotron radiation.} | ||||||
BibTeX:
@proceedings{Ueda08_1,
author = {Ueda, K.},
title = {{Photoemission and coincidence studies on gas-phase molecules}},
journal = {Appl. Phys. A},
series= {The 15th international conference on vacuum ultraviolet radiation physics: VUV XV},
publisher = {Springer},
year = {2008},
volume = {92},
issue = {3},
pages = {487},
numpages = {8},
note = {experiment},
doi = {https://doi.org/10.1007/s00339-008-4552-9}
}
|
||||||
| Y. Morishita, N. Saito, I.H. Suzuki, H. Fukuzawa, X.-J. Liu, K. Sakai, G. Prümper, K. Ueda, H. Iwayama, K. Nagaya, M. Yao, K. Kreidi, M. Schöffler, T. Jahnke, S. Schössler, R. Dörner, T. Weber, J. Harries & Y. Tamenori | Evidence of interatomic Coulombic decay in ArKr after Ar 2p Auger decay | 2008 | J. Phys. B: At. Mol. Opt. Phys. 41, 025101 |
|||
| Abstract: {We have identified interatomic Coulombic decay (ICD) processes in the ArKr dimer following Ar 2p Auger decay, using momentum-resolved electron-ion-ion coincidence spectroscopy and simultaneously determining the kinetic energy of the ICD electron and the KER between Ar2+ and Kr+. We find that the spin-conserved ICD processes in which Ar2+(3p-33d) 1P and 3P decay to Ar2+(3p-2)1D and 3P, respectively, ionizing the Kr atom, are significantly stronger than the spin-flip ICD processes in which Ar2+(3p-33d) 1P and 3P decay to Ar2+(3p-2)3P and 1D, respectively.} | ||||||
BibTeX:
@article{Morishita08,
author = {Morishita, Y. and Saito, N. and Suzuki, I. H. and Fukuzawa, H. and Liu, X.-J. and Sakai, K. and Prümper, G. and Ueda, K. and Iwayama, H. and Nagaya, K. and Yao, M. and Kreidi, K. and Schöffler, M. and Jahnke, T. and Schössler, S. and Dörner, R. and Weber, T. and Harries, J. and Tamenori, Y.},
title = {{Evidence of interatomic Coulombic decay in ArKr after Ar 2p Auger decay}},
journal = {J. Phys. B: At. Mol. Opt. Phys.},
publisher = {IOP},
year = {2008},
volume = {41},
issue = {2},
pages = {025101},
numpages = {5},
note = {experiment},
doi = {https://doi.org/10.1088/0953-4075/41/2/025101}
}
|
||||||
| K. Kreidi, T. Jahnke, Th. Weber, T. Havermeier, R.E. Grisenti, X.-J. Liu, Y. Morisita, S. Schössler, L. Ph.H. Schmidt, M. Schöffler, M. Odenweller, N. Neumann, L. Foucar, J. Titze, B. Ulrich, F. Sturm, C. Stuck, R. Wallauer, S. Voss, I. Lauter, H.K. Kim, M. Rudloff, H. Fukuzawa, G. Prümper, N. Saito, K. Ueda, A. Czasch, O. Jagutzki, H. Schmidt-Böcking, S.K. Semenov, N.A. Cherepkov & R. Dörner | Localization of inner-shell photoelectron emission and interatomic Coulombic decay in Ne2 | 2008 | J. Phys. B: At. Mol. Opt. Phys. 41, 101002 |
|||
| Abstract: {We used cold target recoil ion momentum spectroscopy (COLTRIMS) to investigate the decay of Ne2 after K-shell photoionization. The breakup into Ne1+/Ne2+ shows interatomic Coulombic decay (ICD) occurring after a preceding atomic Auger decay. The molecular frame angular distributions of the photoelectron and the ICD electron show distinct, asymmetric features, which imply localization of the K-vacancy created at one of the two atomic sites of the Ne2 and an emission of the ICD electron from a localized site. The experimental results are supported by calculations in the frozen core Hartree-Fock approach.} | ||||||
BibTeX:
@article{Kreidi08_1,
author = {Kreidi, K. and Jahnke, T. and Weber, Th. and Havermeier, T. and Grisenti, R. E. and Liu, X.-J. and Morisita, Y. and Schössler, S. and Schmidt, L.Ph.H. and Schöffler, M. and Odenweller, M. and Neumann, N. and Foucar, L. and Titze, J. and Ulrich, B. and Sturm, F. and Stuck, C. and Wallauer, R. and Voss, S. and Lauter, I. and Kim, H. K. and Rudloff, M. and Fukuzawa, H. and Prümper, G. and Saito, N. and Ueda, K. and Czasch, A. and Jagutzki, O. and Schmidt-Böcking, H. and Semenov, S. K. and Cherepkov, N. A. and Dörner, R.},
title = {{Localization of inner-shell photoelectron emission and interatomic Coulombic decay in Ne2}},
journal = {J. Phys. B: At. Mol. Opt. Phys.},
publisher = {IOP},
year = {2008},
volume = {41},
issue = {10},
pages = {101002},
numpages = {4},
note = {experiment},
doi = {https://doi.org/10.1088/0953-4075/41/10/101002}
}
|
||||||
| M. Hoener, C. Bostedt, S. Schorb, H. Thomas, L. Foucar, O. Jagutzki, H. Schmidt-Böcking, R. Dörner & T. Möller | From fission to explosion: Momentum-resolved survey over the Rayleigh instability barrier | 2008 | Phys. Rev. A 78, 021201(R) |
|||
| Abstract: {The spatial fragmentation patterns of clusters have been investigated around the Rayleigh instability barrier with a momentum-resolving reaction microscope akin to cold target recoil ion momentum spectroscopy (COLTRIMS). Liquidlike Ne and solid Xe clusters are studied in order to alter the short-range interaction. In the fission regime the neon clusters show spatially anisotropic fragmentation from an expanded geometry as predicted by the liquid drop model, whereas the xenon data suggest a charge separation from neighboring atom positions. For cluster explosion, both systems exhibit an isotropic fragment distribution in agreement with theoretical predictions. The results show how the atom mobility influences the fragmentation dynamics.} | ||||||
BibTeX:
@article{Hoener08,
author = {Hoener, M. and Bostedt, C. and Schorb, S. and Thomas, H. and Foucar, L. and Jagutzki, O. and Schmidt-Böcking, H. and Dörner, R. and Möller, T.},
title = {{From fission to explosion: Momentum-resolved survey over the Rayleigh instability barrier}},
journal = {Phys. Rev. A},
publisher = {American Physical Society},
year = {2008},
volume = {78},
issue = {2},
pages = {021201(R)},
numpages = {4},
note = {experiment},
doi = {https://doi.org/10.1103/PhysRevA.78.021201}
}
|
||||||
| E.F. Aziz, N. Ottosson, M. Faubel, I.V. Hertel & B. Winter | Interaction between liquid water and hydroxide revealed by core-hole de-excitation | 2008 | Nature 455, 89 |
|||
| Abstract: {The hydroxide ion plays an important role in many chemical and biochemical processes in aqueous solution. But our molecular-level understanding of its unusual and fast transport in water, and of the solvation patterns that allow fast transport, is far from complete. One proposal seeks to explain the properties and behaviour of the hydroxide ion by essentially regarding it as a water molecule that is missing a proton, and by inferring transport mechanisms and hydration structures from those of the excess proton. A competing proposal invokes instead unique and interchanging hydroxide hydration complexes, particularly the hypercoordinated OH-(H2O)4 species and tri-coordinated OH-(H2O)3 that can form a transient hydrogen bond between the H atom of the OH- and a neighbouring water molecule. Here we report measurements of core-level photoelectron emission and intermolecular Coulombic decay for an aqueous hydroxide solution, which show that the hydrated hydroxide ion is capable of transiently donating a hydrogen bond to surrounding water molecules. In agreement with recent experimental studies of hydroxide solutions, our finding thus supports the notion that the hydration structure of the hydroxide ion cannot be inferred from that of the hydrated excess proton.} | ||||||
BibTeX:
@article{Aziz08,
author = {Aziz, E. F. and Ottosson, N. and Faubel, M. and Hertel, I. V. and Winter, B.},
title = {{Interaction between liquid water and hydroxide revealed by core-hole de-excitation}},
journal = {Nature},
publisher = {Nature Research},
year = {2008},
volume = {455},
pages = {89},
numpages = {3},
note = {experiment},
doi = {https://doi.org/10.1038/nature07252}
}
|
||||||
| B. Winter | Liquid microjet for photoelectron spectroscopy | 2009 | Nucl. Instrum. Methods Phys. Res. A 601, 139 |
|||
| Abstract: {Photoelectron spectroscopy from highly volatile liquids, especially from water and aqueous solutions, has recently become possible due to the development of the vacuum liquid microjet in combination of high-brilliance synchrotron radiation. The present status of this rapidly growing field is reported here, with an emphasize on the method's sensitivity for detecting local electronic structure, and for monitoring ultrafast dynamical processes in aqueous solution exploiting core-level resonant excitation.} | ||||||
BibTeX:
@article{Winter09,
author = {Winter, B.},
title = {{Liquid microjet for photoelectron spectroscopy}},
journal = {Nucl. Instrum. Methods Phys. Res. A},
publisher = {Elsevier},
year = {2009},
volume = {601},
issue = {1-2},
pages = {139},
numpages = {12},
note = {experiment},
doi = {https://doi.org/10.1016/j.nima.2008.12.108}
}
|
||||||
| O. Björneholm, G. Öhrwall & M. Tchaplyguine | Free clusters studied by core-level spectroscopies | 2009 | Nucl. Instrum. Methods Phys. Res. A 601, 161 |
|||
| Abstract: {In this review we describe the development and current status of free clusters studied using core-level spectroscopies. This topic ranges from simple model systems, such as rare gas clusters, to molecular clusters, and clusters of solids, held together by ionic, covalent and metallic bonding.} | ||||||
BibTeX:
@article{Bjorneholm09,
author = {Björneholm, O. and Öhrwall, G. and Tchaplyguine, M},
title = {{Free clusters studied by core-level spectroscopies}},
journal = {Nucl. Instrum. Methods Phys. Res. A},
publisher = {Elsevier},
year = {2009},
volume = {601},
issue = {1-2},
pages = {161},
numpages = {21},
note = {experiment},
doi = {https://doi.org/10.1016/j.nima.2008.12.222}
}
|
||||||
| B. Ulrich, A. Vredenborg, A. Malakzadeh, M. Meckel, K. Cole, M. Smolarski, Z. Chang, T. Jahnke & R. Dörner | Double-ionization mechanisms of the argon dimer in intense laser fields | 2010 | Phys. Rev. A 82, 013412 |
|||
| Abstract: {We have measured the two-site double ionization of argon dimers by ultrashort laser pulses leading to fragmentation into two singly charged argon ions. Contrary to the expectations from a pure Coulomb explosion following rapid removal of one electron from each of the atoms, we find three distinct peaks in the kinetic energy release (KER) distribution. By measuring the angular distribution of the fragment ions and the vector momentum of one of the emitted electrons for circular and linear laser polarization, we are able to unravel the ionization mechanisms leading to the three features in the KER. The most abundant one results from tunnel ionization at one site followed by charge-enhanced tunnel ionization of the second atom. The second mechanism, which leads to a higher KER we identify as sequential tunnel ionization of both atoms accompanied by excitation. The third mechanism is present with linearly polarized light only. It is most likely a frustrated triple ionization, where the third electron does not escape but is trapped in a Rydberg state.} | ||||||
BibTeX:
@article{Ulrich10,
author = {Ulrich, B. and Vredenborg, A. and Malakzadeh, A. and Meckel, M. and Cole, K. and Smolarski, M. and Chang, Z. and Jahnke, T. and Dörner, R.},
title = {{Double-ionization mechanisms of the argon dimer in intense laser fields}},
journal = {Phys. Rev. A},
publisher = {American Physical Society},
year = {2010},
volume = {82},
issue = {1},
pages = {013412},
numpages = {8},
note = {experiment},
doi = {https://doi.org/10.1103/PhysRevA.82.013412}
}
|
||||||
| M. Tchaplyguine, G. Öhrwall & O. Björneholm | Photoelectron Spectroscopy of Free Clusters | 2010 | Handbook of Nanophysics: Clusters and Fullerenes , 7-1 |
|||
| Abstract: { } | ||||||
BibTeX:
@inbook{Tchaplyguine10,
author = {Tchaplyguine, M. and Öhrwall, G. and Björneholm, O.},
title = {{Photoelectron Spectroscopy of Free Clusters}},
journal = {Handbook of Nanophysics: Clusters and Fullerenes},
publisher = {CRC Press},
year = {2010},
pages = {7-1},
numpages = {32},
note = {experiment},
doi = {doi/10.1201/9781420075557-13}
}
|
||||||
| G. Öhrwall, N. Ottosson, W. Pokapanich, S. Legendre, S. Svensson & O. Björneholm | Charge Dependence of Solvent-Mediated Intermolecular Coster-Kronig Decay Dynamics of Aqueous Ions | 2010 | J. Phys. Chem. B 114, 17057 |
|||
| Abstract: {The 2s and 2p photoelectron spectra have been measured for Na+, Mg2+, and Al3+ ions in aqueous solution. In all cases, the 2s lines are significantly broader than the 2p features, which is attributed to a shorter lifetime of the respective 2s hole. Since intraionic Coster-Kronig decay channels from the (2s)-1 state are closed for free Na+, Mg2+, and Al3+ ions, this is evidence for an intermolecular Coster-Kronig-like process, reminiscent of intermolecular Coulombic decay (ICD), involving neighboring water solvent molecules. The observed 2s Lorentzian line widths correspond to lifetimes of the (2s)-1 state of 3.1, 1.5, and 0.98 fs for the solvated Na, Mg, and Al ions, respectively.} | ||||||
BibTeX:
@article{Ohrwall10,
author = {Öhrwall, G. and Ottosson, N. and Pokapanich, W. and Legendre, S. and Svensson, S. and Björneholm, O.},
title = {{Charge Dependence of Solvent-Mediated Intermolecular Coster-Kronig Decay Dynamics of Aqueous Ions}},
journal = {J. Phys. Chem. B},
publisher = {American Chemical Society},
year = {2010},
volume = {114},
issue = {51},
pages = {17057},
numpages = {5},
note = {experiment},
doi = {https://doi.org/10.1021/jp108956v}
}
|
||||||
| M. Mucke, M. Braune, S. Barth, M. Förstel, T. Lischke, V. Ulrich, T. Arion, U. Becker, A. Bradshaw & U. Hergenhahn | A hitherto unrecognized source of low-energy electrons in water | 2010 | Nat. Phys. 6, 143 |
|||
| Abstract: {Low-energy electrons are the most abundant product of ionizing radiation in condensed matter. The origin of these electrons is most commonly understood to be secondary electrons ionized from core or valence levels by incident radiation and slowed by multiple inelastic scattering events. Here, we investigate the production of low-energy electrons in amorphous medium-sized water clusters, which simulate water molecules in an aqueous environment. We identify a hitherto unrecognized extra source of low-energy electrons produced by a non-local autoionization process called intermolecular coulombic decay (ICD). The unequivocal signature of this process is observed in coincidence measurements of low-energy electrons and photoelectrons generated from inner-valence states with vacuum-ultraviolet light. As ICD is expected to take place universally in weakly bound aggregates containing light atoms between carbon and neon in the periodic table these results could have implications for our understanding of ionization damage in living tissues.} | ||||||
BibTeX:
@article{Mucke10,
author = {Mucke, M. and Braune, M. and Barth, S. and Förstel, M. and Lischke, T. and Ulrich, V. and Arion, T. and Becker, U. and Bradshaw, A and Hergenhahn, U.},
title = {{A hitherto unrecognized source of low-energy electrons in water}},
journal = {Nat. Phys.},
publisher = {Nature Research},
year = {2010},
volume = {6},
pages = {143},
numpages = {4},
note = {experiment},
doi = {https://doi.org/10.1038/nphys1500}
}
|
||||||
| T.D. Märk & P. Scheier | Ionization dynamics: Unexpected electrons | 2010 | Nat. Phys. 6, 82 |
|||
| Abstract: {Radiation damage to living tissues occurs not only by the high-energy incident particles of this radiation but also by low-energy secondary electrons that they produce. Two studies now demonstrate that a large fraction of these electrons are generated by a relatively unusual autoionization process known as intermolecular Coulombic decay.} | ||||||
BibTeX:
@article{Maerk10,
author = {Märk, T. D. and Scheier, P.},
title = {{Ionization dynamics: Unexpected electrons}},
journal = {Nat. Phys.},
publisher = {Nature Research},
year = {2010},
volume = {6},
pages = {82},
numpages = {2},
note = {experiment},
doi = {https://doi.org/10.1038/nphys1526}
}
|
||||||
| B. Manschwetus, H. Rottke, G. Steinmeyer, L. Foucar, A. Czasch, H. Schmidt-Böcking & W. Sandner | Mechanisms underlying strong-field double ionization of argon dimers | 2010 | Phys. Rev. A 82, 013413 |
|||
| Abstract: {We investigate double ionization of argon dimers in high-intensity ultrashort Ti:sapphire laser pulses. We are able to identify several strong-field excitation pathways of the dimer that terminate in atomic ion pairs from a Coulomb explosion. The explosion starts from two-site double-ionized dimers and from one-site double-ionized ones after radiative charge transfer at small internuclear separation. One-site double ionization is accomplished by laser-induced charge transfer in the high-intensity laser pulse following two-site double ionization. The highest energy ion pairs we observed can be attributed to “frustrated triple ionization” of the argon dimer.} | ||||||
BibTeX:
@article{Manschwetus10,
author = {Manschwetus, B. and Rottke, H. and Steinmeyer, G. and Foucar, L. and Czasch, A. and Schmidt-Böcking, H. and Sandner, W.},
title = {{Mechanisms underlying strong-field double ionization of argon dimers}},
journal = {Phys. Rev. A},
publisher = {American Physical Society},
year = {2010},
volume = {82},
issue = {1},
pages = {013413},
numpages = {9},
note = {experiment},
doi = {https://doi.org/10.1103/PhysRevA.82.013413}
}
|
||||||
| T. Jahnke, H. Sann, T. Havermeier, K. Kreidi, C. Stuck, M. Meckel, M. Schöffler, N. Neumann, R. Wallauer, S. Voss, A. Czasch, O. Jagutzki, A. Malakzadeh, F. Afaneh, Th. Weber, H. Schmidt-Böcking & R. Dörner | Ultrafast energy transfer between water molecules | 2010 | Nat. Phys. 6, 139 |
|||
| Abstract: {At the transition from the gas to the liquid phase of water, a wealth of new phenomena emerge, which are absent for isolated H2O molecules. Many of those are important for the existence of life, for astrophysics and atmospheric science. In particular, the response to electronic excitation changes completely as more degrees of freedom become available. Here we report the direct observation of an ultrafast transfer of energy across the hydrogen bridge in (H2O)2 (a so-called water dimer). This intermolecular coulombic decay leads to an ejection of a low-energy electron from the molecular neighbour of the initially excited molecule. We observe that this decay is faster than the proton transfer that is usually a prominent pathway in the case of electronic excitation of small water clusters and leads to dissociation of the water dimer into two H2O+ ions. As electrons of low energy (~0.7-20 eV) have recently been found to efficiently break-up DNA constituents, the observed decay channel might contribute as a source of electrons that can cause radiation damage in biological matter.} | ||||||
BibTeX:
@article{Jahnke10,
author = {Jahnke, T. and Sann, H. and Havermeier, T. and Kreidi, K. and Stuck, C. and Meckel, M. and Schöffler, M. and Neumann, N. and Wallauer, R. and Voss, S. and Czasch, A. and Jagutzki, O. and Malakzadeh, A. and Afaneh, F. and Weber, Th. and Schmidt-Böcking, H. and Dörner, R.},
title = {{Ultrafast energy transfer between water molecules}},
journal = {Nat. Phys.},
publisher = {Nature Research},
year = {2010},
volume = {6},
pages = {139},
numpages = {4},
note = {experiment},
doi = {https://doi.org/10.1038/nphys1498}
}
|
||||||
| M. Hoener, D. Rolles, A. Aguilar, R.C. Bilodeau, D. Esteves, P. Olalde Velasco, Z.D. Pešić, E. Red & N. Berrah | Site-selective ionization and relaxation dynamics in heterogeneous nanosystems | 2010 | Phys. Rev. A 81, 021201(R) |
|||
| Abstract: {We investigated energy and charge transfer mechanisms as well as fragmentation dynamics in site-selectively ionized heterogeneous core-shell clusters using a high-resolution photoelectron-ion coincidence technique. We show that after inner-shell photoionization, energy or charge is transferred to neighboring atoms and that the subsequent charge localization depends on the site of ionization. Cluster bulk ionization leads to more distinct fragmentation channels than surface ionization. We attribute this to different electronic decay, charge localization, and fragmentation times and conclude that charge transfer and fragmentation dynamics are strongly influenced by the environment of the initially ionized atom.} | ||||||
BibTeX:
@article{Hoener10,
author = {Hoener, M. and Rolles, D. and Aguilar, A. and Bilodeau, R. C. and Esteves, D. and Velasco, P. Olalde and Pešić, Z. D. and Red, E. and Berrah, N.},
title = {{Site-selective ionization and relaxation dynamics in heterogeneous nanosystems}},
journal = {Phys. Rev. A},
publisher = {American Physical Society},
year = {2010},
volume = {81},
issue = {2},
pages = {021201(R)},
numpages = {4},
note = {experiment},
doi = {https://doi.org/10.1103/PhysRevA.81.021201}
}
|
||||||
| I. Higuchi, T. Ouchi, K. Sakai, H. Fukuzawa, X.-J. Liu, K. Ueda, H. Iwayama, K. Nagaya, M. Yao, D. Ding, D. Zhang, Y. Tamenori & N. Saito | Radiative charge transfer and interatomic Coulombic decay following direct double photoionization of neon dimers | 2010 | J. Phys.: Conf. Ser. 235, 012015 |
|||
| Abstract: {We have investigated charge separation Ne+-Ne+ and Ne2+-Ne+ from Ne2 after direct double photoionization and compared them with those after 1s photoionization followed by KLL Auger decay and also with those after 2p photoionization of Ar2 followed by LMM Auger decay. The Ne+-Ne+ separation takes place via radiative charge transfer from one-site two-hole states Ne2+(2p4)-Ne, whereas the Ne2+-Ne+ separation takes place via interatomic Coulombic decay from one-site two-hole states Ne2+(2s12p5)-Ne.} | ||||||
BibTeX:
@proceedings{Higuchi10,
author = {Higuchi, I. and Ouchi, T. and Sakai, K. and Fukuzawa, H. and Liu, X.-J. and Ueda, K. and Iwayama, H. and Nagaya, K. and Yao, M. and Ding, D. and Zhang, D. and Tamenori, Y. and Saito, N.},
title = {{Radiative charge transfer and interatomic Coulombic decay following direct double photoionization of neon dimers}},
journal = {J. Phys.: Conf. Ser.},
series= {International Workshop on Electronic Spectroscopy for Gas-phase Molecules and Solid Surfaces (IWES2009)},
publisher = {IOP},
year = {2010},
volume = {235},
pages = {012015},
numpages = {7},
note = {experiment},
doi = {https://doi.org/10.1088/1742-6596/235/1/012015}
}
|
||||||
| T. Havermeier, T. Jahnke, K. Kreidi, R. Wallauer, S. Voss, M. Schöffler, S. Schössler, L. Foucar, N. Neumann, J. Titze, H. Sann, M. Kühnel, J. Voigtsberger, J.H. Morilla, W. Schöllkopf, H. Schmidt-Böcking, R.E. Grisenti & R. Dörner | Interatomic Coulombic Decay following Photoionization of the Helium Dimer: Observation of Vibrational Structure | 2010 | Phys. Rev. Lett. 104, 133401 |
|||
| Abstract: {Using synchrotron radiation we simultaneously ionize and excite one helium atom of a helium dimer (He2) in a shakeup process. The populated states of the dimer ion [i.e., He*+(n=2,3)-He] are found to deexcite via interatomic Coulombic decay. This leads to the emission of a second electron from the neutral site and a subsequent Coulomb explosion. In this Letter we present a measurement of the momenta of fragments that are created during this reaction. The electron energy distribution and the kinetic energy release of the two He+ ions show pronounced oscillations which we attribute to the structure of the vibrational wave function of the dimer ion.} | ||||||
BibTeX:
@article{Havermeier10_1,
author = {Havermeier, T. and Jahnke, T. and Kreidi, K. and Wallauer, R. and Voss, S. and Schöffler, M. and Schössler, S. and Foucar, L. and Neumann, N. and Titze, J. and Sann, H. and Kühnel, M. and Voigtsberger, J. and Morilla, J. H. and Schöllkopf, W. and Schmidt-Böcking, H. and Grisenti, R. E. and Dörner, R.},
title = {{Interatomic Coulombic Decay following Photoionization of the Helium Dimer: Observation of Vibrational Structure}},
journal = {Phys. Rev. Lett.},
publisher = {American Physical Society},
year = {2010},
volume = {104},
pages = {133401},
numpages = {4},
note = {experiment},
doi = {https://doi.org/10.1103/PhysRevLett.104.133401}
}
|
||||||
| B. Shepperson, J. Liu, Ellis, A.M. & S. Yang | Ionization of Doped Helium Nanodroplets: Residual Helium Attached to Diatomic Cations and Their Clusters | 2011 | J. Phys. Chem. A 115, 7010 |
|||
| Abstract: {Electron impact ionization of helium nanodroplets containing a dopant, M, can lead to the detection of both M+ and helium-solvated cations of the type M+·Hen in the gas phase. The observation of helium-doped ions, HenM+, has the potential to provide information on the aftermath of the charge transfer process that leads to ion production from the helium droplet. Here we report on helium attachment to the ions from four common diatomic dopants, M = N2, O2, CO, and NO. For experiments carried out with droplets with an average size of 7500 helium atoms, the monomer cations show little tendency to attach and retain helium atoms on their journey out of the droplet. By way of contrast, the corresponding cluster cations, Mn+, where n≥2, all show a clear affinity for helium and form HemMn+ cluster ions. The stark difference between the monomer and cluster ions is attributed to more effective cooling of the latter in the aftermath of the ionization event.} | ||||||
BibTeX:
@article{Shepperson11,
author = {Shepperson, B. and Liu, J. and Ellis, A. M., and Yang, S.},
title = {{Ionization of Doped Helium Nanodroplets: Residual Helium Attached to Diatomic Cations and Their Clusters}},
journal = {J. Phys. Chem. A},
publisher = {American Chemical Society},
year = {2011},
volume = {115},
issue = {25},
pages = {7010},
numpages = {7},
note = {experiment},
doi = {https://doi.org/10.1021/jp112204e}
}
|
||||||
| R. Seidel, S. Thürmer & B. Winter | Photoelectron Spectroscopy Meets Aqueous Solution: Studies from a Vacuum Liquid Microjet | 2011 | J. Phys. Chem. Lett. 2, 633 |
|||
| Abstract: {Characterization of the structure and properties of matter would be incomplete without the detailed knowledge of electronic structure, and yet, for aqueous solutions, not even the binding energies of the valence electrons are generally known. Thus, fundamental interactions between solute electronic structure and water, essentially the key to chemical reactivity, have remained poorly understood. This work describes how, by the development of the vacuum liquid microjet technique for X-ray photoelectron spectroscopy, electronic structure measurements from aqueous solutions have advanced to date. Direct and resonant second-order electron emission processes are discussed in light of the specific electron structure information accessible from aqueous solutions. Several examples of solutes in their natural aqueous environment will be presented along with future research directions and prevailing challenges in the field.} | ||||||
BibTeX:
@article{Seidel11,
author = {Seidel, R. and Thürmer, S. and Winter, B.},
title = {{Photoelectron Spectroscopy Meets Aqueous Solution: Studies from a Vacuum Liquid Microjet}},
journal = {J. Phys. Chem. Lett.},
publisher = {American Chemical Society},
year = {2011},
volume = {2},
pages = {633},
numpages = {9},
note = {experiment},
doi = {https://doi.org/10.1021/jz101636y}
}
|
||||||
| H.K. Kim, J. Titze, M. Schöffler, F. Trinter, M. Waitz, J. Voigtsberger, H. Sann, M. Meckel, Ch. Stuck, U. Lenz, M. Odenweller, N. Neumann, S. Schössler, K. Ullmann-Pfleger, B. Ulrich, R.C. Fraga, N. Petridis, D. Metz, A. Jung, R. Grisenti, A. Czasch, O. Jagutzki, L. Schmidt, T. Jahnke, H. Schmidt-Böcking & R. Dörner | Enhanced production of low energy electrons by alpha particle impact | 2011 | Proc. Natl. Acad. Sci. U.S.A. 108, 11821 |
|||
| Abstract: {Radiation damage to living tissue stems not only from primary ionizing particles but to a substantial fraction from the dissociative attachment of secondary electrons with energies below the ionization threshold. We show that the emission yield of those low energy electrons increases dramatically in ion-atom collisions depending on whether or not the target atoms are isolated or embedded in an environment. Only when the atom that has been ionized and excited by the primary particle impact is in immediate proximity of another atom is a fragmentation route known as interatomic Coulombic decay (ICD) enabled. This leads to the emission of a low energy electron. Over the past decade ICD was explored in several experiments following photoionization. Most recent results show its observation even in water clusters. Here we show the quantitative role of ICD for the production of low energy electrons by ion impact, thus approaching a scenario closer to that of radiation damage by alpha particles: We choose ion energies on the maximum of the Bragg peak where energy is most efficiently deposited in tissue. We compare the electron production after colliding He+ ions on isolated Ne atoms and on Ne dimers (Ne2). In the latter case the Ne atom impacted is surrounded by a most simple environment already opening ICD as a deexcitation channel. As a consequence, we find a dramatically enhanced low energy electron yield. The results suggest that ICD may have a significant influence on cell survival after exposure to ionizing radiation.} | ||||||
BibTeX:
@article{Kim11,
author = {Kim, H. K. and Titze, J. and Schöffler, M. and Trinter, F. and Waitz, M. and Voigtsberger, J. and Sann, H. and Meckel, M. and Stuck, Ch. and Lenz, U. and Odenweller, M. and Neumann, N. and Schössler, S. and Ullmann-Pfleger, K. and Ulrich, B. and Fraga, R. C. and Petridis, N. and Metz, D. and Jung, A. and Grisenti, R. and Czasch, A. and Jagutzki, O. and Schmidt, L. and Jahnke, T. and Schmidt-Böcking, H. and Dörner, R.},
title = {{Enhanced production of low energy electrons by alpha particle impact}},
journal = {Proc. Natl. Acad. Sci. U.S.A.},
publisher = {Natl. Acad. Sci. USA},
year = {2011},
volume = {108},
issue = {29},
pages = {11821},
numpages = {4},
note = {experiment},
doi = {https://doi.org/10.1073/pnas.1104382108}
}
|
||||||
| U. Hergenhahn | Interatomic and Intermolecular Coulombic Decay: The Early Years | 2011 | J. Electron Spectrosc. Relat. Phenom. 184, 78 |
|||
| Abstract: {Autoionization is an important pathway for the relaxation of electronically excited states. In weakly bonded matter, efficient autoionization channels have been found, in which not only the initially excited state, but also neighbouring atoms or molecules take part. Since their theoretical prediction in 1997 these processes are known as Interatomic or Intermolecular Coulombic Decay (ICD). The author summarizes the experimental research on ICD up to the presence. Experiments on inner valence ICD in rare gas clusters, on cascade ICD after Auger decay and on ICD of satellite states are explicitly discussed. First experiments on water clusters and on solutes will be reviewed. An outlook on other non-local autoionization processes and on future directions of ICD research closes the article} | ||||||
BibTeX:
@article{Hergenhahn11,
author = {Hergenhahn, U.},
title = {{Interatomic and Intermolecular Coulombic Decay: The Early Years}},
journal = {J. Electron Spectrosc. Relat. Phenom.},
publisher = {Elsevier},
year = {2011},
volume = {184},
issue = {3-6},
pages = {78},
numpages = {13},
note = {experiment},
doi = {https://doi.org/10.1016/j.elspec.2010.12.020}
}
|
||||||
| G.A. Grieves & T.M. Orlando | Intermolecular Coulomb decay at weakly coupled heterogeneous interfaces | 2011 | Phys. Rev. Lett. 107, 016104 |
|||
| Abstract: {Surface ejection of H+(H2O)n=1-8 from low energy electron irradiated water clusters adsorbed on graphite and graphite with overlayers of Ar, Kr or Xe results from intermolecular Coulomb decay (ICD) at the mixed interface. Inner valence holes in water (2a1-1), Ar (3s-1), Kr (4s-1) and Xe (5s-1) correlate with the cluster appearance thresholds and initiate ICD. Proton transfer occurs during or immediately after ICD and the resultant Coulomb explosion leads to H+(H2O)n=1-8 desorption with kinetic energies that vary with initiating state, final state and inter-atomic/molecular distances.} | ||||||
BibTeX:
@article{Grieves11,
author = {Grieves, G. A. and Orlando, T. M.},
title = {{Intermolecular Coulomb decay at weakly coupled heterogeneous interfaces}},
journal = {Phys. Rev. Lett.},
publisher = {American Physical Society},
year = {2011},
volume = {107},
issue = {1},
pages = {016104},
numpages = {4},
note = {experiment},
doi = {https://doi.org/10.1103/PhysRevLett.107.016104}
}
|
||||||
| M. Förstel, M. Mucke, T. Arion, A.M. Bradshaw & U. Hergenhahn | Autoionization mediated by electron transfer | 2011 | Phys. Rev. Lett. 106, 033402 |
|||
| Abstract: {Electron-electron coincidence spectra of Ar-Kr clusters after photoionization have been measured. An electron with the kinetic energy range from 0 to approximately 1 eV is found in coincidence with the Ar3s cluster photoelectron. The low kinetic energy electron can be attributed to an Ar+Kr++Kr+ final state which forms after electron transfer mediated decay. This autoionization mechanism results from a concerted transition involving three different atoms in a van der Waals cluster; it was predicted theoretically, but hitherto not observed.} | ||||||
BibTeX:
@article{Forstel11,
author = {Förstel, M. and Mucke, M. and Arion, T. and Bradshaw, A. M. and Hergenhahn, U.},
title = {{Autoionization mediated by electron transfer}},
journal = {Phys. Rev. Lett.},
publisher = {AIP},
year = {2011},
volume = {106},
issue = {3},
pages = {033402},
numpages = {4},
note = {experiment},
doi = {https://doi.org/10.1103/PhysRevLett.106.033402}
}
|
||||||
| T. Arion, M. Mucke, M. Förstel, A.M. Bradshaw & U. Hergenhahn | Interatomic Coulombic decay in mixed NeKr clusters | 2011 | J. Chem. Phys. 134, 074306 |
|||
| Abstract: {We report the occurrence of interatomic Coulombic decay (ICD) in mixed NeKr clusters. A well-defined feature ranging from 9 to 12 eV in kinetic energy is observed in coincidence with the Ne 2s photoelectrons. It derives from an ICD process, in which an initial Ne 2s vacancy is filled by a Ne 2p electron and an electron is emitted from a 4p level on a neighboring Kr atom. We have studied the dependence of the effect on photon energy, cluster composition, and cluster size. Interestingly, the ICD electron energy increases slightly and grows a shoulder on going from 2% to 5% Kr in the coexpansion process, which we interpret in terms of surface versus bulk effects.} | ||||||
BibTeX:
@article{Arion11,
author = {Arion, T. and Mucke, M. and Förstel, M. and Bradshaw, A. M. and Hergenhahn, U.},
title = {{Interatomic Coulombic decay in mixed NeKr clusters}},
journal = {J. Chem. Phys.},
publisher = {AIP},
year = {2011},
volume = {134},
issue = {7},
pages = {074306},
numpages = {6},
note = {experiment},
doi = {https://doi.org/10.1063/1.3552082}
}
|
||||||
| W. Pokapanich, N. Ottosson, S. Svensson, G. Öhrwall, B. Winter & O. Björneholm | Bond-Breaking, Electron-Pushing and Proton-Pulling: Active and Passive Roles in the Interaction between Aqueous Ions and Water as Manifested in the O1s Auger Decay | 2012 | J. Phys. Chem. B 116, 3 |
|||
| Abstract: {A core-ionized H2O molecule in liquid water primarily relaxes through normal Auger decay, leading to a two-hole final state in which both valence holes are localized on the same water molecule. Electronic coupling to the environment, however, allows for alternative decays resembling Intermolecular Coulombic Decay (ICD), producing final states with one of the holes delocalized on a neighboring water molecule. Here we present an experimental study of such minority processes, which adds to our understanding of dynamic interactions of electronically excited H2O molecules with their local surrounding in liquid water and aqueous solution. We show that the solvation of metal-halide salts considerably influences these minority decay channels from the water O 1s-1 state. By breaking water-water bonds, both the metal cations and halide anions are found to reduce the decay into water-water delocalized states, thus having a “passive” effect on the Auger spectrum. The halide anions also play an “active” role by opening a new ICD-like decay pathway into water-halide delocalized states. The importance of this contribution increases from F- to I-, which we suggest to be caused by a directional polarization of the halide anion towards the core-ionized H2O+ cation in the intermediate state of the Auger process. This increases the electronic overlap between the two centers and makes delocalized decays more probable. We furthermore show that F-, the smallest and most strongly hydrated of the halides, plays an additional role as proton puller during the core-hole lifetime, resulting in proton dynamics on the low femtosecond time scale. Our results represent a step forward toward a better understanding of how aqueous solutions, when exposed to soft X-rays, channel excess energy. This has implications for several aspects of physical and radiation chemistry, as well as biology.} | ||||||
BibTeX:
@article{Pokapanich12,
author = {Pokapanich, W. and Ottosson, N. and Svensson, S. and Öhrwall, G. and Winter, B. and Björneholm, O.},
title = {{Bond-Breaking, Electron-Pushing and Proton-Pulling: Active and Passive Roles in the Interaction between Aqueous Ions and Water as Manifested in the O1s Auger Decay}},
journal = {J. Phys. Chem. B},
publisher = {American Chemical Society},
year = {2012},
volume = {116},
issue = {1},
pages = {3},
numpages = {6},
note = {experiment},
doi = {https://doi.org/10.1021/jp2041247}
}
|
||||||
| N. Ottosson, G. Öhrwall & O. Björneholm | Ultrafast charge delocalization dynamics in aqueous electrolytes: New insights from Auger electron spectroscopy | 2012 | Chem. Phys. Lett. 543, 1 |
|||
| Abstract: {We review the basic principles of ultrafast charge delocalization phenomena in aqueous electrolytes following core-level photoionization and resonant core-level excitations, and describe how these processes can be probed using Auger electron spectroscopy. The use of the core-hole clock method to extract dynamical information from Auger spectra is described. By a number of examples we demonstrate how the efficiency for ultrafast charge transfer phenomena on the low femtosecond timescale is determined not only by factors such as charge, polarizability and solvated radius of the ionic solutes but also by the dominant interactions of the ionized site with its surroundings in the intermediate state.} | ||||||
BibTeX:
@article{Ottosson12,
author = {Ottosson, N. and Öhrwall, G. and Björneholm, O.},
title = {{Ultrafast charge delocalization dynamics in aqueous electrolytes: New insights from Auger electron spectroscopy}},
journal = {Chem. Phys. Lett.},
publisher = {Elsevier},
year = {2012},
volume = {543},
pages = {1},
numpages = {11},
note = {experiment},
doi = {https://doi.org/10.1016/j.cplett.2012.05.051}
}
|
||||||
| U. Hergenhahn | Production of low kinetic energy electrons and energetic ion pairs by Intermolecular Coulombic Decay | 2012 | Int. J. Radiat. Biol. 88, 871 |
|||
| Abstract: {Purpose: The paper gives an introduction into Interatomic and Intermolecular Coulombic Decay (ICD). ICD is an autoionization process, which contrary to Auger decay involves neighbouring sites of the initial vacancy as an integral part of the decay transition. As a result of ICD, slow electrons are produced which are known to be active in radiation damage. The author summarizes the properties of ICD and reviews a number of important experiments done in recent years. Materials and methods: Intermolecular Coulombic Decay can generally take place in weakly bonded aggregates in the presence of ionizing particles or ionizing radiation. Examples collected here mostly use soft X-rays produced by synchrotron radiation to ionize, and use rare-gas clusters, water clusters or solutes in a liquid jet to observe ICD after irradiation. Results: Intermolecular Coulombic Decay is initiated by single ionization into an excited state. The subsequent relaxation proceeds via an ultra-fast energy transfer to a neighbouring site, where a second ionization occurs. Secondary electrons from ICD have clearly been identified in numerous systems. ICD can take place after primary ionization, as the second step of a decay cascade which also involves Auger decay, or after resonant excitation with an energy which exceeds the ionization potential of the system. Conclusions: ICD is expected to play a role whenever particles or radiation with photon energies above the ionization energies for inner valence electrons are present in weakly bonded matter, e.g. biological tissue. The process produces at the same time a slow electron and two charged atomic or molecular fragments, which will lead to structural changes around the ionized site.} | ||||||
BibTeX:
@article{Hergenhahn12,
author = {Hergenhahn, U.},
title = {{Production of low kinetic energy electrons and energetic ion pairs by Intermolecular Coulombic Decay}},
journal = {Int. J. Radiat. Biol.},
publisher = {Taylor & Francis},
year = {2012},
volume = {88},
issue = {12},
pages = {871},
numpages = {13},
note = {experiment},
doi = {https://doi.org/10.3109/09553002.2012.698031}
}
|
||||||
| A. Golan & M. Ahmed | Ionization of Water Clusters is Mediated by Exciton Energy Transfer from Argon Clusters | 2012 | J. Phys. Chem. Lett. 3, 458 |
|||
| Abstract: {The exciton energy deposited in an argon cluster, (Arn ,< n=20>) using VUV radiation is transferred to softly ionize doped water clusters, ((H2O)n, n=1-9) leading to the formation of non-fragmented clusters. Following the initial excitation, electronic energy is channeled to ionize the doped water cluster while evaporating the Ar shell, allowing identification of fragmented and complete water cluster ions. Examination of the photoionization efficiency curve shows that cluster evaporation from excitons located above 12.6 eV are not enough to cool the energized water cluster ion, and leads to their dissociation to (H2O)n-2H+ (protonated) clusters.} | ||||||
BibTeX:
@article{Golan12,
author = {Golan, A and Ahmed, M.},
title = {{Ionization of Water Clusters is Mediated by Exciton Energy Transfer from Argon Clusters}},
journal = {J. Phys. Chem. Lett.},
publisher = {American Chemical Society},
year = {2012},
volume = {3},
issue = {4},
pages = {458},
numpages = {5},
note = {experiment},
doi = {https://doi.org/10.1021/jz2016654}
}
|
||||||
| S. Yan, P. Zhang, X. Ma, S. Xu, B. Li, X.L. Zhu, W.T. Feng, S.F. Zhang, D.M. Zhao, R. Zhang, D. Guo & H.P. Liu | Observation of interatomic Coulombic decay and electron-transfer-mediated decay in high-energy electron-impact ionization of Ar2 | 2013 | Phys. Rev. A 88, 042712 |
|||
| Abstract: {We measured the kinetic energy distributions of the fragment ions of doubly and quadruply ionized argon dimers using 3000 eV electron impact. For the dissociation of (Ar2)2+, the peak that indicates radiative charge transfer is observed, where the outer-shell ionization (dominant in highly charged ion collision) and the inner-shell ionization (preferential in x-ray experiments) have approximately equal contributions. For the dissociation of (Ar2)4+, the interatomic Coulombic decay and electron-transfer-mediated decay are first observed in the electron-impact process.} | ||||||
BibTeX:
@article{Yan13,
author = {Yan, S. and Zhang, P. and Ma, X. and Xu, S. and Li, B. and Zhu, X. L. and Feng, W. T. and Zhang, S. F. and Zhao, D. M. and Zhang, R. and Guo, D. and Liu, H. P.},
title = {{Observation of interatomic Coulombic decay and electron-transfer-mediated decay in high-energy electron-impact ionization of Ar2}},
journal = {Phys. Rev. A},
publisher = {American Physical Society},
year = {2013},
volume = {88},
issue = {4},
pages = {042712},
numpages = {5},
note = {experiment},
doi = {https://doi.org/10.1103/PhysRevA.88.042712}
}
|
||||||
| M. Patanen, Ch. Nicolas, X.-J. Liu, O. Travnikova & C. Miron | Structural characterization of small Xe clusters using their 5s correlation satellite electron spectrum | 2013 | Phys. Chem. Chem. Phys. 15, 10112 |
|||
| Abstract: {The Xe 5s photoelectron spectrum and 5p4nl correlation satellites have been studied in small Xe clusters of an average size of about 15 atoms. The satellite structures are interpreted with the help of the atomic Xe lines. Transition energy shifts between the atomic and the corner/edge/face/bulk components in clusters are divided into polarization screening and exchange interaction energy. Interestingly enough, the ratios between corner/edge/face/bulk polarization screening and exchange interaction energies are found to reflect the ratios of the coordination numbers of corner/edge/face/bulk atoms in these small icosahedral cluster structures.} | ||||||
BibTeX:
@article{Patanen13,
author = {Patanen, M. and Nicolas, Ch. and Liu, X.-J. and Travnikova, O. and Miron, C.},
title = {{Structural characterization of small Xe clusters using their 5s correlation satellite electron spectrum}},
journal = {Phys. Chem. Chem. Phys.},
publisher = {RSC},
year = {2013},
volume = {15},
issue = {25},
pages = {10112},
numpages = {6},
note = {experiment},
doi = {https://doi.org/10.1039/C3CP50249J}
}
|
||||||
| P. O'Keeffe, E. Ripani, P. Bolognesi, M. Coreno, M. Devetta, C. Callegari, M. Di Fraia, K.C. Prince, R. Richter, M. Alagia, A. Kivimäki & L. Avaldi | The Role of the Partner Atom and Resonant Excitation Energy in Interatomic Coulombic Decay in Rare Gas Dimers | 2013 | J. Phys. Chem. Lett. 4, 1797 |
|||
| Abstract: {We provide experimental evidence for Interatomic Coulombic Decay (ICD) in mixed rare gas dimers following resonant Auger decay. A velocity map imaging apparatus together with a cooled supersonic beam containing Ar2 and NeAr dimers was used to record the energy and angular distributions of electrons in coincidence with two mass selected ions following the excitation of a number of resonances converging to the 2p3/2-1 threshold using synchrotron radiation. It is shown that the ICD process can be controlled by the choice of the partner atom in the dimer or of the resonance which triggers the resonant Auger decay.} | ||||||
BibTeX:
@article{OKeeffe13,
author = {O'Keeffe, P. and Ripani, E. and Bolognesi, P. and Coreno, M. and Devetta, M. and Callegari, C. and Di Fraia, M. and Prince, K. C. and Richter, R. and Alagia, M. and Kivimäki, A. and Avaldi, L.},
title = {{The Role of the Partner Atom and Resonant Excitation Energy in Interatomic Coulombic Decay in Rare Gas Dimers}},
journal = {J. Phys. Chem. Lett.},
publisher = {American Chemical Society},
year = {2013},
volume = {4},
issue = {11},
pages = {1797},
numpages = {5},
note = {experiment},
doi = {https://doi.org/10.1021/jz400671h}
}
|
||||||
| K. Nagaya, A. Sugishima, H. Iwayama, H. Murakami, M. Yao, H. Fukuzawa, X.-J. Liu, K. Motomura, K. Ueda, N. Saito, L. Foucar, A. Rudenko, M. Kurka, K.-U. Kühne, J. Ullrich, A. Czasch, R. Dörner, R. Feifel, M. Nagasono, A. Higashiya, M. Yabashi, T. Ishikawa, T. Togashi, H. Kimura & H. Ohashi | Unusual under-threshold ionization of neon clusters studied by ion spectroscopy | 2013 | J. Phys. B: At. Mol. Opt. Phys. 46, 164023 |
|||
| Abstract: {We carried out time-of-flight mass spectrometry for neon clusters that were exposed to intense free electron laser pulses with the wavelength of 62 nm, which induce optical transition from the ground state (2s2 2p6) to an excited state (2s2 2p55 nl ) in the Ne atoms. In contrast to Ne+ ions produced by two-photon absorption from isolated Ne atoms, the Ne+ ion yield from Ne clusters shows a linear dependence on the laser intensity (I). We discuss the ionization mechanisms which give the linear behaviour with respect to I and expected features in the electron emission spectrum.} | ||||||
BibTeX:
@article{Nagaya13,
author = {Nagaya, K. and Sugishima, A. and Iwayama, H. and Murakami, H. and Yao, M. and Fukuzawa, H. and Liu, X.-J. and Motomura, K. and Ueda, K. and Saito, N. and Foucar, L. and Rudenko, A. and Kurka, M. and Kühne, K.-U. and Ullrich, J. and Czasch, A. and Dörner, R. and Feifel, R. and Nagasono, M. and Higashiya, A. and Yabashi, M. and Ishikawa, T. and Togashi, T. and Kimura, H. and Ohashi, H.},
title = {{Unusual under-threshold ionization of neon clusters studied by ion spectroscopy}},
journal = {J. Phys. B: At. Mol. Opt. Phys.},
publisher = {IOP},
year = {2013},
volume = {46},
issue = {16},
pages = {164023},
numpages = {5},
note = {experiment},
doi = {https://doi.org/10.1088/0953-4075/46/16/164023}
}
|
||||||
| K. Lange & E.F. Aziz | Electronic structure of ions and molecules in solution: a view from modern soft X-ray spectroscopies | 2013 | Chem. Soc. Rev. 42, 6840 |
|||
| Abstract: {Soft X-ray spectroscopies are powerful tools for probing the local electronic and molecular orbital structures of materials in different phases and various environments. While modern spectroscopic tools using soft X-ray synchrotron photons perspicuously reveal the molecular orbital (MO) structure in detail, structures remain widely unknown in the liquid phase since many of these techniques could only be applied to solutions very recently. Furthermore, the interactions and dynamics of molecules in the liquid phase are especially complicated compared to those in gas and solid phases and thereby impede the understanding of functional materials in solution. This review presents recent developments using soft X-ray radiation for probing the electronic structure of ions and molecules in solution. The presented X-ray absorption, emission, and photo-electron spectroscopy studies exhibit the powerful contributions of soft X-ray liquid spectroscopies in the last few years.} | ||||||
BibTeX:
@article{Lange13,
author = {Lange, K. and Aziz, E. F.},
title = {{Electronic structure of ions and molecules in solution: a view from modern soft X-ray spectroscopies}},
journal = {Chem. Soc. Rev.},
publisher = {RSC},
year = {2013},
volume = {42},
issue = {16},
pages = {6840},
numpages = {20},
note = {experiment},
doi = {https://doi.org/10.1039/C3CS00008G}
}
|
||||||
| J. Kočišek, J. Lengyel, M. Fárník & P. Slavíček | Energy and charge transfer in ionized argon coated water clusters | 2013 | J. Chem. Phys. 139, 214308 |
|||
| Abstract: {We investigate the electron ionization of clusters generated in mixed Ar-water expansions. The electron energy dependent ion yields reveal the neutral cluster composition and structure: water clusters fully covered with the Ar solvation shell are formed under certain expansion conditions. The argon atoms shield the embedded (H2O)n clusters resulting in the ionization threshold above ≈15 eV for all fragments. The argon atoms also mediate more complex reactions in the clusters: e.g., the charge transfer between Ar+ and water occurs above the threshold; at higher electron energies above ∼28 eV, an excitonic transfer process between Ar+∗ and water opens leading to new products ArnH+ and (H2O)nH+. On the other hand, the excitonic transfer from the neutral Ar∗ state at lower energies is not observed although this resonant process was demonstrated previously in a photoionization experiment. Doubly charged fragments (H2O)nH22+ and (H2O)n2+ ions are observed and Intermolecular Coulomb decay (ICD) processes are invoked to explain their thresholds. The Coulomb explosion of the doubly charged cluster formed within the ICD process is prevented by the stabilization effect of the argon solvent.} | ||||||
BibTeX:
@article{Kocisek13,
author = {Kočišek, J. and Lengyel, J. and Fárník, M. and Slavíček, P.},
title = {{Energy and charge transfer in ionized argon coated water clusters}},
journal = {J. Chem. Phys.},
publisher = {AIP},
year = {2013},
volume = {139},
issue = {21},
pages = {214308},
numpages = {7},
note = {experiment},
doi = {https://doi.org/10.1063/1.4834715}
}
|
||||||
| K. Kimura, H. Fukuzawa, T. Tachibana, Y. Ito, S. Mondal, M. Okunishi, M. Schöffler, J. Williams, Y. Jiang, Y. Tamenori, N. Saito & K. Ueda | Controlling Low-energy Electron Emission via Resonant-Auger-induced Interatomic Coulombic Decay | 2013 | J. Phys. Chem. Lett. 4, 1838 |
|||
| Abstract: {We have investigated Interatomic Coulombic Decay (ICD) after resonant Auger decay in Ar2, ArKr and ArXe following 2p3/2→4s and 2p3/2→3d excitations in Ar, using momentum resolved electron-ion-ion coincidence. The results illustrate that ICD induced by the resonant Auger decay is a well-controlled way of producing energy-selected slow electrons at a specific site.} | ||||||
BibTeX:
@article{Kimura13b,
author = {Kimura, K. and Fukuzawa, H. and Tachibana, T. and Ito, Y. and Mondal, S. and Okunishi, M. and Schöffler, M. and Williams, J. and Jiang, Y. and Tamenori, Y. and Saito, N. and Ueda, K.},
title = {{Controlling Low-energy Electron Emission via Resonant-Auger-induced Interatomic Coulombic Decay}},
journal = {J. Phys. Chem. Lett.},
publisher = {American Chemical Society},
year = {2013},
volume = {4},
issue = {11},
pages = {1838},
numpages = {5},
note = {experiment},
doi = {https://doi.org/10.1021/jz4006674}
}
|
||||||
| K. Kimura, H. Fukuzawa, K. Sakai, S. Mondal, E. Kukk, Y. Kono, S. Nagaoka, Y. Tamenori, N. Saito & K. Ueda | Efficient site-specific low-energy electron production via interatomic Coulombic decay following resonant Auger decay in argon dimers | 2013 | Phys. Rev. A 87, 043414 |
|||
| Abstract: {We identified interatomic Coulombic decay (ICD) channels in argon dimers after spectator-type resonant Auger decay 2p-13d→3p-23d,4d in one of the atoms, using momentum-resolved electron-ion-ion coincidence. The results illustrate that the resonant core excitation is a very efficient way of producing slow electrons at a specific site, which may cause localized radiation damage. We find also that ICD rate for 3p-24d is significantly lower than that for 3p-23d.} | ||||||
BibTeX:
@article{Kimura13a,
author = {Kimura, K. and Fukuzawa, H. and Sakai, K. and Mondal, S. and Kukk, E. and Kono, Y. and Nagaoka, S. and Tamenori, Y. and Saito, N. and Ueda, K.},
title = {{Efficient site-specific low-energy electron production via interatomic Coulombic decay following resonant Auger decay in argon dimers}},
journal = {Phys. Rev. A},
publisher = {American Physical Society},
year = {2013},
volume = {87},
issue = {4},
pages = {043414},
numpages = {4},
note = {experiment},
doi = {https://doi.org/10.1103/PhysRevA.87.043414}
}
|
||||||
| H.K. Kim, H. Gassert, M.S. Schöffler, J.N. Titze, M. Waitz, J. Voigtsberger, F. Trinter, J. Becht, A. Kalinin, N. Neumann, C. Zhou, L. Ph.H. Schmidt, O. Jagutzki, A. Czasch, H. Merabet, H. Schmidt-Böcking, T. Jahnke, A. Cassimi & R. Dörner | Ion-impact-induced interatomic Coulombic decay in neon and argon dimers | 2013 | Phys. Rev. A 88, 042707 |
|||
| Abstract: {We investigate the contribution of interatomic Coulombic decay induced by ion impact in neon and argon dimers (Ne2 and Ar2) to the production of low-energy electrons. Our experiments cover a broad range of perturbation strengths and reaction channels. We use 11.37 MeV/u S14+, 0.125 MeV/u He1+, 0.1625 MeV/u He1+ and 0.150 MeV/u He2+ as projectiles and study ionization, single and double electron transfer to the projectile, as well as projectile electron loss processes. The application of a COLTRIMS reaction microscope enables us to retrieve the three-dimensional momentum vectors of the ion pairs of the fragmenting dimer into Neq+/Ne1+ and Arq+/Ar1+ (q = 1, 2, 3) in coincidence with at least one emitted electron.} | ||||||
BibTeX:
@article{Kim13,
author = {Kim, H. K. and Gassert, H. and Schöffler, M. S. and Titze, J. N. and Waitz, M. and Voigtsberger, J. and Trinter, F. and Becht, J. and Kalinin, A. and Neumann, N. and Zhou, C. and Schmidt, L.Ph.H. and Jagutzki, O. and Czasch, A. and Merabet, H. and Schmidt-Böcking, H. and Jahnke, T. and Cassimi, A. and Dörner, R.},
title = {{Ion-impact-induced interatomic Coulombic decay in neon and argon dimers}},
journal = {Phys. Rev. A},
publisher = {American Physical Society},
year = {2013},
volume = {88},
issue = {4},
pages = {042707},
numpages = {9},
note = {experiment},
doi = {https://doi.org/10.1103/PhysRevA.88.042707}
}
|
||||||
| M. Förstel, T. Arion & U. Hergenhahn | Measuring the efficiency of interatomic Coulombic decay in Ne clusters | 2013 | J. Electron Spectrosc. Relat. Phenom. 191, 16 |
|||
| Abstract: {The efficiency of interatomic coulombic decay (ICD) in Neon clusters with a mean size of ⟨N⟩=480 is measured directly. By detecting the photoelectrons and the ICD electrons in coincidence and normalizing their ratio using the detection probability of the respective electrons we show that the relaxation of Ne 2s vacancies in Ne clusters by ICD has an efficiency of unity.} | ||||||
BibTeX:
@article{Forstel13,
author = {Förstel, M. and Arion, T. and Hergenhahn, U.},
title = {{Measuring the efficiency of interatomic Coulombic decay in Ne clusters}},
journal = {J. Electron Spectrosc. Relat. Phenom.},
publisher = {Elsevier},
year = {2013},
volume = {191},
pages = {16},
numpages = {4},
note = {experiment},
doi = {https://doi.org/10.1016/j.elspec.2013.11.002}
}
|
||||||
| S. Yan, P. Zhang, X. Ma, S. Xu, S.X. Tian, B. Li, X.L. Zhu, W.T. Feng & D.M. Zhao | Dissociation mechanisms of the Ar trimer induced by a third atom in high-energy electron-impact ionization | 2014 | Phys. Rev. A 89, 062707 |
|||
| Abstract: {We experimentally studied the dissociation dynamics of a highly charged Ar3 cluster initiated by a high-energy electron. The dissociation patterns of the correlated ions from a two-body and a three-body Coulombic explosion (CE) of (Ar3)2+ suggest that predissociation alters the evolution of radiative charge transfer. The three-body CE in (Ar3)4+ and (Ar3)5+ is driven, after double ionization of one constituent Ar atom, by single ionization with a simultaneous interatomic Coulombic decay process.} | ||||||
BibTeX:
@article{Yan14,
author = {Yan, S. and Zhang, P. and Ma, X. and Xu, S. and Tian, S. X. and Li, B. and Zhu, X. L. and Feng, W. T. and Zhao, D. M.},
title = {{Dissociation mechanisms of the Ar trimer induced by a third atom in high-energy electron-impact ionization}},
journal = {Phys. Rev. A},
publisher = {American Physical Society},
year = {2014},
volume = {89},
issue = {6},
pages = {062707},
numpages = {5},
note = {experiment},
doi = {https://doi.org/10.1103/PhysRevA.89.062707}
}
|
||||||
| F. Trinter, M.S. Schöffler, H.K. Kim, F.P. Sturm, K. Cole, N. Neumann, A. Vredenborg, J. Williams, I. Bocharova, R. Guillemin, M. Simon, A. Belkacem, A.L. Landers, Th. Weber, H. Schmidt-Böcking, R. Dörner & T. Jahnke | Resonant Auger decay driving intermolecular Coulombic decay in molecular dimers | 2014 | Nature 505, 664 |
|||
| Abstract: {In 1997, it was predicted that an electronically excited atom or molecule placed in a loosely bound chemical system (such as a hydrogen-bonded or van-der-Waals-bonded cluster) could efficiently decay by transferring its excess energy to a neighbouring species that would then emit a low-energy electron. This intermolecular Coulombic decay (ICD) process has since been shown to be a common phenomenon, raising questions about its role in DNA damage induced by ionizing radiation, in which low-energy electrons are known to play an important part. It was recently suggested that ICD can be triggered efficiently and site-selectively by resonantly core-exciting a target atom, which then transforms through Auger decay into an ionic species with sufficiently high excitation energy to permit ICD to occur. Here we show experimentally that resonant Auger decay can indeed trigger ICD in dimers of both molecular nitrogen and carbon monoxide. By using ion and electron momentum spectroscopy to measure simultaneously the charged species created in the resonant-Auger-driven ICD cascade, we find that ICD occurs in less time than the 20 femtoseconds it would take for individual molecules to undergo dissociation. Our experimental confirmation of this process and its efficiency may trigger renewed efforts to develop resonant X-ray excitation schemes for more localized and targeted cancer radiation therapy.} | ||||||
BibTeX:
@article{Trinter14,
author = {Trinter, F. and Schöffler, M. S. and Kim, H. K. and Sturm, F. P. and Cole, K. and Neumann, N. and Vredenborg, A. and Williams, J. and Bocharova, I. and Guillemin, R. and Simon, M. and Belkacem, A. and Landers, A. L. and Weber, Th. and Schmidt-Böcking, H. and Dörner, R. and Jahnke, T.},
title = {{Resonant Auger decay driving intermolecular Coulombic decay in molecular dimers}},
journal = {Nature},
publisher = {Nature Research},
year = {2014},
volume = {505},
issue = {7485},
pages = {664},
numpages = {3},
note = {experiment},
doi = {https://doi.org/10.1038/nature12927}
}
|
||||||
| Y. Ovcharenko, V. Lyamayev, R. Katzy, M. Devetta, A. LaForge, O'Keeffe, O. Plekan, P. Finetti, M. Di Fraia, M. Mudrich, M. Krikunova, P. Piseri, M. Coreno, N. Brauer, T. Mazza, S. Stranges, C. Grazioli, R. Richter, K.C. Prince, M. Drabbels, C. Callegari, F. Stienkemeier & T. Möller | Novel collective autoionization process observed in electron spectra of He clusters | 2014 | Phys. Rev. Lett. 112, 073401 |
|||
| Abstract: {The ionization dynamics of He nanodroplets irradiated with intense femtosecond extreme ultraviolet pulses of up to 1013 W/cm2 power density have been investigated by photoelectron spectroscopy. Helium droplets were resonantly excited to atomiclike 2p states with a photon energy of 21.4 eV below the ionization potential (Ip), and directly into the ionization continuum with 42.8 eV photons. While electron emission following direct ionization above Ip is well explained within a model based on a sequence of direct electron emission events, the resonant excitation provides evidence of a new, collective ionization mechanism involving many excited atomiclike 2p states. With increasing power density the direct photoline due to an interatomic Coulombic decay disappears. It indicates that ionization occurs due to energy exchange between at least three excited atoms proceeding on a femtosecond time scale. In agreement with recent theoretical work the novel ionization process is very efficient and it is expected to be important for many other systems.} | ||||||
BibTeX:
@article{Ovcharenko14,
author = {Ovcharenko, Y. and Lyamayev, V. and Katzy, R. and Devetta, M. and LaForge, A. and O'Keeffe, and Plekan, O. and Finetti, P. and Di Fraia, M. and Mudrich, M. and Krikunova, M. and Piseri, P. and Coreno, M. and Brauer, N. and Mazza, T. and Stranges, S. and Grazioli, C. and Richter, R. and Prince, K. C. and Drabbels, M. and Callegari, C. and Stienkemeier, F. and Möller, T.},
title = {{Novel collective autoionization process observed in electron spectra of He clusters}},
journal = {Phys. Rev. Lett.},
publisher = {American Physical Society},
year = {2014},
volume = {112},
issue = {7},
pages = {073401},
numpages = {5},
note = {experiment},
doi = {https://doi.org/10.1103/PhysRevLett.112.073401}
}
|
||||||
| P. O'Keeffe, A. Ciavardini, E. Ripani, P. Bolognesi, M. Coreno, L. Avaldi, M. Devetta, M. Di Fraia, C. Callegari, K.C. Prince & R. Richter | Experimental investigation of the interatomic Coulombic decay in NeAr dimers | 2014 | Phys. Rev. A 90, 042508 |
|||
| Abstract: {The kinetic-energy distribution of interatomic and -molecular Coulombic decay (ICD) electrons emitted following photoionization of 2s electrons from Ne atoms in NeAr dimers has been measured in a synchrotron radiation experiment with a velocity-map-imaging photoelectron-photoion-coincidence spectrometer. The position of the peak of the experimental distribution agrees well with calculations. The broadening of the distribution to high energies with respect to calculations of the ICD spectrum of the NeAr ν=0 ground state is explained by the contribution to the spectrum due to the population in the excited vibrational states ν=1 and ν=2 of the electron ground state. On the other hand, the broadening on the low-energy side of the measured distribution may be explained by the dimer contracting in the intermediate state before ICD occurs, electrons coming from the ICD to spin-orbit split excited ion states, or a combination of these effects.} | ||||||
BibTeX:
@article{OKeeffe14,
author = {O'Keeffe, P. and Ciavardini, A. and Ripani, E. and Bolognesi, P. and Coreno, M. and Avaldi, L. and Devetta, M. and Di Fraia, M. and Callegari, C. and Prince, K. C. and Richter, R. },
title = {{Experimental investigation of the interatomic Coulombic decay in NeAr dimers}},
journal = {Phys. Rev. A},
publisher = {American Physical Society},
year = {2014},
volume = {90},
issue = {4},
pages = {042508},
numpages = {6},
note = {experiment},
doi = {https://doi.org/10.1103/PhysRevA.90.042508}
}
|
||||||
| A.C. LaForge, M. Drabbels, N.B. Brauer, M. Coreno, M. Devetta, M. Di Fraia, P. Finetti, C. Grazioli, R. Katzy, V. Lyamayev, T. Mazza, M. Mudrich, P. O'Keeffe, Y. Ovcharenko, P. Piseri, O. Plekan, K.C. Prince, R. Richter, S. Stranges, C. Callegari, T. Möller & F. Stienkemeier | Collective Autoionization in Multiply-Excited Systems: A novel ionization process observed in Helium Nanodroplets | 2014 | Sci. Rep. 4, 3621 |
|||
| Abstract: {Free electron lasers (FELs) offer the unprecedented capability to study reaction dynamics and image the structure of complex systems. When multiple photons are absorbed in complex systems, a plasma-like state is formed where many atoms are ionized on a femtosecond timescale. If multiphoton absorption is resonantly-enhanced, the system becomes electronically-excited prior to plasma formation, with subsequent decay paths which have been scarcely investigated to date. Here, we show using helium nanodroplets as an example that these systems can decay by a new type of process, named collective autoionization. In addition, we show that this process is surprisingly efficient, leading to ion abundances much greater than that of direct single-photon ionization. This novel collective ionization process is expected to be important in many other complex systems, e.g. macromolecules and nanoparticles, exposed to high intensity radiation fields.} | ||||||
BibTeX:
@article{LaForge14,
author = {LaForge, A. C. and Drabbels, M. and Brauer, N. B. and Coreno, M. and Devetta, M. and Di Fraia, M. and Finetti, P. and Grazioli, C. and Katzy, R. and Lyamayev, V. and Mazza, T. and Mudrich, M. and O'Keeffe, P. and Ovcharenko, Y. and Piseri, P. and Plekan, O. and Prince, K. C. and Richter, R. and Stranges, S. and Callegari, C. and Möller, T. and Stienkemeier, F.},
title = {{Collective Autoionization in Multiply-Excited Systems: A novel ionization process observed in Helium Nanodroplets}},
journal = {Sci. Rep.},
publisher = {Nature Research},
year = {2014},
volume = {4},
pages = {3621},
numpages = {4},
note = {experiment},
doi = {https://doi.org/10.1038/srep03621}
}
|
||||||
| A. Knie, A. Hans, M. Förstel, U. Hergenhahn, Ph. Schmidt, Ph. Reiß, Ch. Ozga, B. Kambs, F. Trinter, J. Voigtsberger, D. Metz, T. Jahnke, R. Dörner, A.I. Kuleff, L.S. Cederbaum, Ph.V. Demekhin & A. Ehresmann | Detecting ultrafast interatomic electronic processes in media by fluorescence | 2014 | New J. Phys. 16, 102002 |
|||
| Abstract: {Interatomic coulombic decay (ICD), a radiationless transition in weakly bonded systems, such as solutes or van der Waals bound aggregates, is an effective source for electrons of low kinetic energy. So far, the ICD processes could only be probed in ultra-high vacuum by using electron and/or ion spectroscopy. Here we show that resonant ICD processes can also be detected by measuring the subsequently emitted characteristic fluorescence radiation, which makes their study in dense media possible.} | ||||||
BibTeX:
@article{Knie14,
author = {Knie, A. and Hans, A. and Förstel, M. and Hergenhahn, U. and Schmidt, Ph. and Reiß, Ph. and Ozga, Ch. and Kambs, B. and Trinter, F. and Voigtsberger, J. and Metz, D. and Jahnke, T. and Dörner, R. and Kuleff, A. I. and Cederbaum, L. S. and Demekhin, Ph. V. and Ehresmann, A.},
title = {{Detecting ultrafast interatomic electronic processes in media by fluorescence}},
journal = {New J. Phys.},
publisher = {IOP},
year = {2014},
volume = {16},
pages = {102002},
numpages = {9},
note = {experiment},
doi = {https://doi.org/10.1088/1367-2630/16/10/102002}
}
|
||||||
| H.K. Kim, H. Gassert, J.N. Titze, M. Waitz, J. Voigtsberger, F. Trinter, J. Becht, A. Kalinin, N. Neumann, C. Zhou, L. Ph.H. Schmidt, O. Jagutzki, A. Czasch, M. Schöffler, H. Merabet, H. Schmidt-Böcking, T. Jahnke, H.J. Lüdde, A. Cassimi & R. Dörner | Orientation dependence in multiple ionization of He2 and Ne2 induced by fast, highly charged ions: Probing the impact-parameter-dependent ionization probability in 11.37-MeV/u S14+ collisions with He and Ne | 2014 | Phys. Rev. A 89, 022704 |
|||
| Abstract: {We investigate orientation effects in the fragmentation of He2 and Ne2 induced by S14+ projectiles at an impact energy of 11.37 MeV/u. Multiple ionization shows a strong dependence on the orientation of the dimer axis with respect to the projectile beam axis. We attribute these effects to the impact-parameter-dependent ionization probability P(b) for the atomic scattering process S14+ + He and S14+ + Ne and compare our data with a Monte Carlo simulation.} | ||||||
BibTeX:
@article{Kim14,
author = {Kim, H. K. and Gassert, H. and Titze, J. N. and Waitz, M. and Voigtsberger, J. and Trinter, F. and Becht, J. and Kalinin, A. and Neumann, N. and Zhou, C. and Schmidt, L.Ph.H. and Jagutzki, O. and Czasch, A. and Schöffler, M. and Merabet, H. and Schmidt-Böcking, H. and Jahnke, T. and Lüdde, H. J. and Cassimi, A. and Dörner, R.},
title = {{Orientation dependence in multiple ionization of He2 and Ne2 induced by fast, highly charged ions: Probing the impact-parameter-dependent ionization probability in 11.37-MeV/u S14+ collisions with He and Ne}},
journal = {Phys. Rev. A},
publisher = {American Physical Society},
year = {2014},
volume = {89},
issue = {2},
pages = {022704},
numpages = {11},
note = {experiment},
doi = {https://doi.org/10.1103/PhysRevA.89.022704}
}
|
||||||
| E. Keshavarz, H. Farrokhpour, H. Sabzyan, Z. Noorisafa, A. Kivimäki & R. Richter | Core photoionization of the argon dimer in the photon-energy range of 255-340 eV studied by a photoelectron-photoion-photoion coincidence technique | 2014 | Phys. Rev. A 89, 053409 |
|||
| Abstract: {Single-photon multiple ionization of the argon dimer van der Waals complex, Ar2, is studied by the photoelectron-photoion-photoion coincidence technique using synchrotron radiation in the photon-energy range of 255–340 eV, which covers the Ar 2p and Ar 2s ionization continua. Dissociation processes into Ar+ + Ar+, Ar+ + Ar2+, Ar+ + Ar3+, and Ar2+ + Ar2+ ion pair channels are observed. The Ar+ + Ar+ and Ar+ + Ar2+ channels show the most intense ion-ion coincidences, compared to other observed dissociative channels. For the four observed channels the intensities are integrated and compared as functions of photon energy.} | ||||||
BibTeX:
@article{Keshavarz14,
author = {Keshavarz, E. and Farrokhpour, H. and Sabzyan, H. and Noorisafa, Z. and Kivimäki, A. and Richter, R.},
title = {{Core photoionization of the argon dimer in the photon-energy range of 255-340 eV studied by a photoelectron-photoion-photoion coincidence technique}},
journal = {Phys. Rev. A},
publisher = {American Physical Society},
year = {2014},
volume = {89},
issue = {5},
pages = {053409},
numpages = {7},
note = {experiment},
doi = {https://doi.org/10.1103/PhysRevA.89.053409}
}
|
||||||
| S.-J. Seo, S.-M. Han, J.-H. Cho, K. Hyodo, A. Zaboronok, H. You, K. Peach, M.A. Hill & J.-K. Kim | Enhanced production of reactive oxygen species by gadolinium oxide nanoparticles under core-inner-shell excitation by proton or monochromatic X-ray irradiation: implication of the contribution from the interatomic de-excitation-mediated nanoradiator effect to dose enhancement | 2015 | Radiat. Environ. Biophys. 54, 423 |
|||
| Abstract: {Core-inner-valence ionization of high-Z nanoparticle atomic clusters can de-excite electrons through various interatomic de-excitation processes, thereby leading to the ionization of both directly exposed atoms and adjacent neutral atoms within the nanoparticles, and to an enhancement in photon-electron emission, which is termed the nanoradiator effect. To investigate the nanoradiator-mediated dose enhancement in the radio-sensitizing of high-Z nanoparticles, the production of reactive oxygen species (ROS) was measured in a gadolinium oxide nanoparticle (Gd-oxide NP) solution under core-inner-valence excitation of Gd with either 50 keV monochromatic synchrotron X-rays or 45 MeV protons. This measurement was compared with either a radiation-only control or a gadolinium-chelate magnetic resonance imaging contrast agent solution containing equal amounts of gadolinium as the separate atomic species in which Gd-Gd interatomic de-excitations are absent. Ionization excitations followed by ROS measurements were performed on nanoparticle-loaded cells or aqueous solutions. Both photoexcitation and proton impact produced a dose-dependent enhancement in the production of ROS by a range of factors from 1.6 to 1.94 compared with the radiation-only control. Enhanced production of ROS, by a factor of 1.83, was observed from Gd-oxide NP atomic clusters compared with the Gd-chelate molecule, with a Gd concentration of 48 μg/mL in the core-level photon excitation, or by a factor of 1.82 under a Gd concentration of 12 μg/mL for the proton impact at 10 Gy (p < 0.02). The enhanced production of ROS in the irradiated nanoparticles suggests the potential for additional therapeutic dose enhancements in radiation treatment via the potent Gd-Gd interatomic de-excitation-driven nanoradiator effect.} | ||||||
BibTeX:
@article{Seo15,
author = {Seo, S.-J. and Han, S.-M. and Cho, J.-H. and Hyodo, K. and Zaboronok, A. and You, H. and Peach, K. and Hill, M. A. and Kim, J.-K.},
title = {{Enhanced production of reactive oxygen species by gadolinium oxide nanoparticles under core-inner-shell excitation by proton or monochromatic X-ray irradiation: implication of the contribution from the interatomic de-excitation-mediated nanoradiator effect to dose enhancement}},
journal = {Radiat. Environ. Biophys.},
publisher = {Springer},
year = {2015},
volume = {54},
issue = {4},
pages = {423},
numpages = {9},
note = {experiment},
doi = {https://doi.org/10.1007/s00411-015-0612-7}
}
|
||||||
| T. Pflüger, X. Ren & A. Dorn | Electron-impact-induced dissociation of small argon clusters | 2015 | Phys. Rev. A 91, 052701 |
|||
| Abstract: {We study electron-impact-induced dissociation of small van der Waals-bound argon complexes at a projectile energy of 120 eV. Kinetic-energy-release (KER) spectra of the Ar2 and Ar3 parent species for the final charge states 2Ar+, Ar+ + Ar2+, and Ar2+ + Ar+ and electron energies have been measured together with angular distributions of fragment ions. They are used to identify dissociation mechanisms such as interatomic Coulombic decay (ICD).} | ||||||
BibTeX:
@article{Pflueger15,
author = {Pflüger, T. and Ren, X. and Dorn, A.},
title = {{Electron-impact-induced dissociation of small argon clusters}},
journal = {Phys. Rev. A},
publisher = {American Physical Society},
year = {2015},
volume = {91},
issue = {5},
pages = {052701},
numpages = {6},
note = {experiment},
doi = {https://doi.org/10.1103/PhysRevA.91.052701}
}
|
||||||
| M. Mucke, T. Arion, M. Förstel, T. Lischke & U. Hergenhahn | Competition of inelastic electron scattering and Interatomic Coulombic Decay in Ne clusters | 2015 | J. Electron Spectrosc. Relat. Phenom. 200, 232 |
|||
| Abstract: {The creation of slow electrons due to Interatomic Coulombic Decay of 2s vacancies in Ne clusters is quantitatively compared to the slow electron yield by intracluster electron impact ionization. Using electron-electron coincidence spectroscopy, both channels can be separated experimentally. Two cluster size distributions, corresponding to two and five to six filled solvation shells, are probed.} | ||||||
BibTeX:
@article{Mucke15,
author = {Mucke, M. and Arion, T. and Förstel, M. and Lischke, T. and Hergenhahn, U.},
title = {{Competition of inelastic electron scattering and Interatomic Coulombic Decay in Ne clusters}},
journal = {J. Electron Spectrosc. Relat. Phenom.},
publisher = {Elsevier},
year = {2015},
volume = {200},
pages = {232},
numpages = {7},
note = {experiment},
doi = {https://doi.org/10.1016/j.elspec.2015.04.017}
}
|
||||||
| R. Katzy, A.C. LaForge, Y. Ovcharenko, M. Coreno, M. Devetta, M. Di Fraia, M. Drabbels, P. Finetti, V. Lyamayev, T. Mazza, M. Mudrich, P. O'Keeffe, P. Piseri, O. Plekan, K.C. Prince, S. Stranges, C. Callegari, T. Möller & F. Stienkemeier | Migration of surface excitations in highly-excited nanosystems probed by intense resonant XUV radiation | 2015 | J. Phys. B: At. Mol. Opt. Phys. 48, 244011 |
|||
| Abstract: {Ionization dynamics of resonantly excited helium nanodroplets have been studied by intense XUV light. By doping the nanodroplets with atoms that either attach to the surface or submerge into the center of the droplet, one can study the dynamics of excitation and ionization through the droplet. When resonantly exciting the droplet, we observe a strong ionization enhancement for atoms attached to the surface. On the other hand, atoms embedded inside the nanodroplet are less efficiently ionized. We attribute this effect to an ultrafast energy transfer to the surface of the droplet and subsequent Penning ionization of the surface-bound dopant.} | ||||||
BibTeX:
@article{Katzy15,
author = {Katzy, R. and LaForge, A. C. and Ovcharenko, Y. and Coreno, M. and Devetta, M. and Di Fraia, M. and Drabbels, M. and Finetti, P. and Lyamayev, V. and Mazza, T. and Mudrich, M. and O'Keeffe, P. and Piseri, P. and Plekan, O. and Prince, K. C. and Stranges, S. and Callegari, C. and Möller, T. and Stienkemeier, F.},
title = {{Migration of surface excitations in highly-excited nanosystems probed by intense resonant XUV radiation}},
journal = {J. Phys. B: At. Mol. Opt. Phys.},
publisher = {IOP},
year = {2015},
volume = {48},
issue = {24},
pages = {244011},
numpages = {6},
note = {experiment},
doi = {https://doi.org/10.1088/0953-4075/48/24/244011}
}
|
||||||
| W. Iskandar, J. Matsumoto, A. Leredde, X. Fléchard, B. Gervais, S. Guillous, D. Hennecart, A. Méry, J. Rangama, C.L. Zhou, H. Shiromaru & A. Cassimi | Interatomic Coulombic Decay as a New Source of Low Energy Electrons in Slow Ion-Dimer Collisions | 2015 | Phys. Rev. Lett. 114, 033201 |
|||
| Abstract: {We provide the experimental evidence that the single electron capture process in slow collisions between O3+ ions and neon dimer targets leads to an unexpected production of low-energy electrons. This production results from the interatomic Coulombic decay process, subsequent to inner-shell single electron capture from one site of the neon dimer. Although pure one-electron capture from the inner shell is expected to be negligible in the low collision energy regime investigated here, the electron production due to this process overtakes by 1 order of magnitude the emission of Auger electrons by the scattered projectiles after double-electron capture. This feature is specific to low charge states of the projectile: similar studies with Xe20+ and Ar9+ projectiles show no evidence of inner-shell single-electron capture. The dependence of the process on the projectile charge state is interpreted using simple calculations based on the classical over the barrier model.} | ||||||
BibTeX:
@article{Iskandar15,
author = {Iskandar, W. and Matsumoto, J. and Leredde, A. and Fléchard, X. and Gervais, B. and Guillous, S. and Hennecart, D. and Méry, A. and Rangama, J. and Zhou, C. L. and Shiromaru, H. and Cassimi, A.},
title = {{Interatomic Coulombic Decay as a New Source of Low Energy Electrons in Slow Ion-Dimer Collisions}},
journal = {Phys. Rev. Lett.},
publisher = {American Physical Society},
year = {2015},
volume = {114},
issue = {3},
pages = {033201},
numpages = {5},
note = {experiment},
doi = {https://doi.org/10.1103/PhysRevLett.114.033201}
}
|
||||||
| U. Frühling, F. Trinter, F. Karimi, J.B. Williams & T. Jahnke | Time-resolved studies of Interatomic Coulombic Decay | 2015 | J. Electron Spectrosc. Relat. Phenom. 204, 237 |
|||
| Abstract: {Interatomic Coulombic Decay (ICD) is a decay mechanism occurring in loosely bound matter, e.g. in systems bound by van der Waals-forces or hydrogen bonds. In many such cases the decay time is similar to the time scale of nuclear motion during the decay. As the efficiency of ICD strongly depends on the internuclear distance of the atoms or molecules involved in the decay, an overall non-trivial temporal decay behavior arises. The progress of examining the time-domain aspects of Interatomic Coulombic Decay is summarized in this short topical review with a special emphasis on experiments that are now feasible due to the developments of free-electron lasers.} | ||||||
BibTeX:
@article{Frueling15,
author = {Frühling, U. and Trinter, F. and Karimi, F. and Williams, J. B. and Jahnke, T.},
title = {{Time-resolved studies of Interatomic Coulombic Decay}},
journal = {J. Electron Spectrosc. Relat. Phenom.},
publisher = {Elsevier},
year = {2015},
volume = {204},
pages = {237},
numpages = {8},
note = {experiment},
doi = {https://doi.org/10.1016/j.elspec.2015.06.012}
}
|
||||||
| E. Alizadeh, T.M. Orlando & L. Sanche | Biomolecular Damage Induced by Ionizing Radiation: The Direct and Indirect Effects of Low-Energy Electrons on DNA | 2015 | Annu. Rev. Phys. Chem. 66, 379 |
|||
| Abstract: {Many experimental and theoretical advances have recently allowed the study of direct and indirect effects of low-energy electrons (LEEs) on DNA damage. In an effort to explain how LEEs damage the human genome, researchers have focused efforts on LEE interactions with bacterial plasmids, DNA bases, sugar analogs, phosphate groups, and longer DNA moieties. Here, we summarize the current understanding of the fundamental mechanisms involved in LEE-induced damage of DNA and complex biomolecule films. Results obtained by several laboratories on films prepared and analyzed by different methods and irradiated with different electron-beam current densities and fluencies are presented. Despite varied conditions (e.g., film thicknesses and morphologies, intrinsic water content, substrate interactions, and extrinsic atmospheric compositions), comparisons show a striking resemblance in the types of damage produced and their yield functions. The potential of controlling this damage using molecular and nanoparticle targets with high LEE yields in targeted radiation-based cancer therapies is also discussed.} | ||||||
BibTeX:
@article{Alizadeh15,
author = {Alizadeh, E. and Orlando, T. M. and Sanche, L.},
title = {{Biomolecular Damage Induced by Ionizing Radiation: The Direct and Indirect Effects of Low-Energy Electrons on DNA}},
journal = {Annu. Rev. Phys. Chem.},
year = {2015},
volume = {66},
pages = {379},
numpages = {20},
note = {experiment},
doi = {https://doi.org/10.1146/annurev-physchem-040513-103605}
}
|
||||||
| X. Ren, E.J. Al Maalouf, A. Dorn & S. Denifl | Direct evidence of two interatomic relaxation mechanisms in argon dimers ionized by electron impact | 2016 | Nat. Commun. 7, 11093 |
|||
| Abstract: {In weakly bound systems like liquids and clusters electronically excited states can relax in inter-particle reactions via the interplay of electronic and nuclear dynamics. Here we report on the identification of two prominent examples, interatomic Coulombic decay (ICD) and radiative charge transfer (RCT), which are induced in argon dimers by electron collisions. After initial ionization of one dimer constituent ICD and RCT lead to the ionization of its neighbour either by energy transfer to or by electron transfer from the neighbour, respectively. By full quintuple-coincidence measurements, we unambiguously identify ICD and RCT, and trace the relaxation dynamics as function of the collisional excited state energies. Such interatomic processes multiply the number of electrons and shift their energies down to the critical 1-10 eV range, which can efficiently cause chemical degradation of biomolecules. Therefore, the observed relaxation channels might contribute to cause efficient radiation damage in biological systems.} | ||||||
BibTeX:
@article{Ren16,
author = {Ren, X. and Al Maalouf, E. J. and Dorn, A. and Denifl, S.},
title = {{Direct evidence of two interatomic relaxation mechanisms in argon dimers ionized by electron impact}},
journal = {Nat. Commun.},
publisher = {Nature Research},
year = {2016},
volume = {7},
issue = {10},
pages = {11093},
numpages = {6},
note = {experiment},
doi = {https://doi.org/10.1038/ncomms11093}
}
|
||||||
| D. Iablonskyi, K. Nagaya, H. Fukuzawa, K. Motomura, Y. Kumagai, S. Mondal, T. Tachibana, T. Takanashi, T. Nishiyama, K. Matsunami, P. Johnsson, P. Piseri, G. Sansone, A. Dubrouil, M. Reduzzi, P. Carpeggiani, C. Vozzi, M. Devetta, M. Negro, F. Calegari, A. Trabattoni, M.C. Castrovilli, D. Faccialá, Y. Ovcharenko, T. Möller, M. Mudrich, F. Stienkemeier, M. Coreno, M. Alagia, B. Schütte, N. Berrah, A.I. Kuleff, G. Jabbari, C. Callegari, O. Plekan, P. Finetti, C. Spezzani, E. Ferrari, E. Allaria, G. Penco, C. Serpico, G. De Ninno, I. Nikolov, B. Diviacco, S. Di Mitri, L. Giannessi, K.C. Prince & K. Ueda | Slow Interatomic Coulombic Decay of Multiply Excited Neon Clusters | 2016 | Phys. Rev. Lett. 117, 276806 |
|||
| Abstract: {Ne clusters (~5000 atoms) were resonantly excited (2p → 3s) by intense free electron laser (FEL) radiation at FERMI. Such multiply excited clusters can decay nonradiatively via energy exchange between at least two neighboring excited atoms. Benefiting from the precise tunability and narrow bandwidth of seeded FEL radiation, specific sites of the Ne clusters were probed. We found that the relaxation of cluster surface atoms proceeds via a sequence of interatomic or intermolecular Coulombic decay (ICD) processes while ICD of bulk atoms is additionally affected by the surrounding excited medium via inelastic electron scattering. For both cases, cluster excitations relax to atomic states prior to ICD, showing that this kind of ICD is rather slow (picosecond range). Controlling the average number of excitations per cluster via the FEL intensity allows a coarse tuning of the ICD rate.} | ||||||
BibTeX:
@article{Iablonskyi16,
author = {Iablonskyi, D. and Nagaya, K. and Fukuzawa, H. and Motomura, K. and Kumagai, Y. and Mondal, S. and Tachibana, T. and Takanashi, T. and Nishiyama, T. and Matsunami, K. and Johnsson, P. and Piseri, P. and Sansone, G. and Dubrouil, A. and Reduzzi, M. and Carpeggiani, P. and Vozzi, C. and Devetta, M. and Negro, M. and Calegari, F. and Trabattoni, A. and Castrovilli, M. C. and Faccialá, D. and Ovcharenko, Y. and Möller, T. and Mudrich, M. and Stienkemeier, F. and Coreno, M. and Alagia, M. and Schütte, B. and Berrah, N. and Kuleff, A. I. and Jabbari, G. and Callegari, C. and Plekan, O. and Finetti, P. and Spezzani, C. and Ferrari, E. and Allaria, E. and Penco, G. and Serpico, C. and De Ninno, G. and Nikolov, I. and Diviacco, B. and Di Mitri, S. and Giannessi, L. and Prince, K. C. and Ueda, K.},
title = {{Slow Interatomic Coulombic Decay of Multiply Excited Neon Clusters}},
journal = {Phys. Rev. Lett.},
publisher = {American Physical Society},
year = {2016},
volume = {117},
issue = {27},
pages = {276806},
numpages = {5},
note = {experiment},
doi = {https://doi.org/10.1103/PhysRevLett.117.276806}
}
|
||||||
| A. Hans, A. Knie, M. Förstel, Ph. Schmidt, Ph. Reiß, Ch. Ozga, U. Hergenhahn & A. Ehresmann | Determination of absolute cross sections for cluster-specific decays | 2016 | J. Phys. B: At. Mol. Opt. Phys. 49, 105101 |
|||
| Abstract: {Fluorescence spectrometry is used to determine absolute cross sections of cluster-specific decay processes following photon excitation. Absolute values for selected processes in partially condensed supersonic jets are determined using atomic benchmarks. This method is applicable to a wide variety of processes in clusters in which a photon is emitted. In a proof-of-principle experiment, absolute cross sections of processes in two prototype systems were measured: (I) inner-valence excitation and ionization of Ar clusters and (II) resonant interatomic Coulombic decay (rICD) in Ne clusters. Example II is the first measurement of absolute cross sections of ICD whatsoever.} | ||||||
BibTeX:
@article{Hans16a,
author = {Hans, A. and Knie, A. and Förstel, M. and Schmidt, Ph. and Reiß, Ph. and Ozga, Ch. and Hergenhahn, U. and Ehresmann, A.},
title = {{Determination of absolute cross sections for cluster-specific decays}},
journal = {J. Phys. B: At. Mol. Opt. Phys.},
publisher = {IOP},
year = {2016},
volume = {49},
pages = {105101},
numpages = {6},
note = {experiment},
doi = {https://doi.org/10.1088/0953-4075/49/10/105101}
}
|
||||||
| M. Shcherbinin, A.C. LaForge, V. Sharma, M. Devetta, R. Richter, R. Moshammer, T. Pfeifer & M. Mudrich | Interatomic Coulombic decay in helium nanodroplets | 2017 | Phys. Rev. A 96, 013407 |
|||
| Abstract: {Interatomic Coulombic decay (ICD) is induced in helium nanodroplets by photoexciting the n=2 excited state of He+ using XUV synchrotron radiation. By recording multiple-coincidence electron and ion images we find that ICD occurs in various locations at the droplet surface, inside the surface region, or in the droplet interior. ICD at the surface gives rise to energetic He+ ions as previously observed for free He dimers. ICD deeper inside leads to the ejection of slow He+ ions due to Coulomb explosion delayed by elastic collisions with neighboring He atoms, and to the formation of Hek+ complexes} | ||||||
BibTeX:
@article{Shcherbinin17,
author = {Shcherbinin, M. and LaForge, A. C. and Sharma, V. and Devetta, M. and Richter, R. and Moshammer, R. and Pfeifer, T. and Mudrich, M.},
title = {{Interatomic Coulombic decay in helium nanodroplets}},
journal = {Phys. Rev. A},
publisher = {American Physical Society},
year = {2017},
volume = {96},
issue = {1},
pages = {013407},
numpages = {5},
note = {experiment},
doi = {https://doi.org/10.1103/PhysRevA.96.013407}
}
|
||||||
| H. Sann, T. Havermeier, H.-K. Kim, F. Sturm, F. Trinter, M. Waitz, S. Zeller, B. Ulrich, M. Meckel, S. Voss, T. Bauer, D. Schneider, H. Schmidt-Böcking, R. Wallauer, M. Schöffler, J.B. Williams, R. Dörner & T. Jahnke | Interatomic Coulombic Decay of HeNe dimers after ionization and excitation of He and Ne | 2017 | Chem. Phys. 482, 221 |
|||
| Abstract: {We study the decay of a helium/neon dimer after ionization and simultaneous excitation of either the neon or the helium atom using Cold Target Recoil Ion Momentum Spectroscopy (COLTRIMS). We find that, depending on the decaying state, either direct Interatomic Coulombic Decay (ICD) (i.e. mediated by a virtual photon exchange), exchange ICD (mediated by electron exchange) or radiative charge transfer occurs. The corresponding channels are identified.} | ||||||
BibTeX:
@article{Sann17,
author = {Sann, H. and Havermeier, T. and Kim, H.-K. and Sturm, F. and Trinter, F. and Waitz, M. and Zeller, S. and Ulrich, B. and Meckel, M. and Voss, S. and Bauer, T. and Schneider, D. and Schmidt-Böcking, H. and Wallauer, R. and Schöffler, M. and Williams, J. B. and Dörner, R. and Jahnke, T.},
title = {{Interatomic Coulombic Decay of HeNe dimers after ionization and excitation of He and Ne}},
journal = {Chem. Phys.},
publisher = {Elsevier},
year = {2017},
volume = {482},
pages = {221},
numpages = {5},
note = {experiment},
doi = {https://doi.org/10.1016/j.chemphys.2016.09.008}
}
|
||||||
| M.N. Pohl, C. Richter, E. Lugovoy, R. Seidel, P. Slavíček, E.F. Aziz, B. Abel, B. Winter & U. Hergenhahn | Sensitivity of Electron Transfer Mediated Decay to Ion Pairing | 2017 | J. Phys. Chem. B 121, 7709 |
|||
| Abstract: {Ion pairing in electrolyte solutions remains a topic of discussion despite a long history of research. Very recently, nearest-neighbor mediated electronic deexcitation processes of core hole vacancies (Electron Transfer Mediated Decay, ETMD) were proposed to carry a spectral fingerprint of local solvation structure and in particular of contact ion pairs. Here, for the first time, we apply electron-electron coincidence detection to a liquid microjet, and record ETMD spectra of Li 1s vacancies in aqueous solutions of lithium chloride (LiCl) in direct comparison to lithium acetate (LiOAc). A change in the ETMD spectrum dependent on the electrolyte anion identity is observed for 4.5 M salt concentration. We discuss these findings within the framework of the formation and presence of contact ion pairs and the unique sensitivity of ETMD spectroscopy to ion pairing.} | ||||||
BibTeX:
@article{Pohl17,
author = {Pohl, M. N. and Richter, C. and Lugovoy, E. and Seidel, R. and Slavíček, P. and Aziz, E. F. and Abel, B. and Winter, B. and Hergenhahn, U.},
title = {{Sensitivity of Electron Transfer Mediated Decay to Ion Pairing}},
journal = {J. Phys. Chem. B},
publisher = {American Chemical Society},
year = {2017},
volume = {121},
pages = {7709},
numpages = {6},
note = {experiment},
doi = {https://doi.org/10.1021/acs.jpcb.7b06061}
}
|
||||||
| T. Ouchi, H. Fukuzawa, K. Sakai, T. Mazza, M. Schöffler, K. Nagaya, Y. Tamenori, N. Saito & K. Ueda | Interatomic Coulombic decay and electron-transfer-mediated decay following triple ionization of Ne2 and NeAr | 2017 | Chem. Phys. 482, 244 |
|||
| Abstract: {We report observations of the interatomic Coulombic decay (ICD) and electron-transfer-mediated decay (ETMD) from the triply charged states in Ne2 and NeAr dimers. The ICD processes leading to fragmentation of Ne3+-Ne into Ne3+-Ne+ and Ne3+-Ar into Ne3+-Ar+, and ETMD processes leading to fragmentation of Ne3+-Ne into Ne2+-Ne2+ are unambiguously identified by electron-ion-ion coincidence spectroscopy in which the kinetic energy of the ICD or ETMD electron and the kinetic energy release between the two fragment ions are measured in coincidence.} | ||||||
BibTeX:
@article{Ouchi17a,
author = {Ouchi, T. and Fukuzawa, H. and Sakai, K. and Mazza, T. and Schöffler, M. and Nagaya, K. and Tamenori, Y. and Saito, N. and Ueda, K.},
title = {{Interatomic Coulombic decay and electron-transfer-mediated decay following triple ionization of Ne2 and NeAr}},
journal = {Chem. Phys.},
publisher = {Elsevier},
year = {2017},
volume = {482},
pages = {244},
numpages = {5},
note = {experiment},
doi = {https://doi.org/10.1016/j.chemphys.2016.09.022}
}
|
||||||
| T. Oelze, B. Schütte, M. Müller, J.P. Müller, M. Wieland, U. Frühling, M. Drescher, A. Al-Shemmary, T. Golz, N. Stojanovic & M. Krikunova | Correlated electronic decay in expanding clusters triggered by intense XUV pulses from a Free-Electron-Laser | 2017 | Sci. Rep. 7, 40736 |
|||
| Abstract: {Irradiation of nanoscale clusters and large molecules with intense laser pulses transforms them into highly-excited non-equilibrium states. The dynamics of intense laser-cluster interaction is encoded in electron kinetic energy spectra, which contain signatures of direct photoelectron emission as well as emission of thermalized nanoplasma electrons. In this work we report on a so far not observed spectrally narrow bound state signature in the electron kinetic energy spectra from mixed Xe core - Ar shell clusters ionized by intense extreme-ultraviolet (XUV) pulses from a free-electron-laser. This signature is attributed to the correlated electronic decay (CED) process, in which an excited atom relaxes and the excess energy is used to ionize the same or another excited atom or a nanoplasma electron. By applying the terahertz field streaking principle we demonstrate that CED-electrons are emitted at least a few picoseconds after the ionizing XUV pulse has ended. Following the recent finding of CED in clusters ionized by intense near-infrared laser pulses, our observation of CED in the XUV range suggests that this process is of general relevance for the relaxation dynamics in laser produced nanoplasmas.} | ||||||
BibTeX:
@article{Oelze17,
author = {Oelze, T. and Schütte, B. and Müller, M. and Müller, J. P. and Wieland, M. and Frühling, U. and Drescher, M. and Al-Shemmary, A. and Golz, T. and Stojanovic, N. and Krikunova, M. },
title = {{Correlated electronic decay in expanding clusters triggered by intense XUV pulses from a Free-Electron-Laser}},
journal = {Sci. Rep.},
publisher = {Nature Research},
year = {2017},
volume = {7},
pages = {40736},
numpages = {8},
note = {experiment},
doi = {https://doi.org/10.1038/srep40736}
}
|
||||||
| A. Hans, L.B. Ltaief, M. Förstel, Ph. Schmidt, Ch. Ozga, Ph. Reiß, X. Holzapfel, C. Küstner-Wetekam, F. Wiegandt, F. Trinter, U. Hergenhahn, T. Jahnke, R. Dörner, A. Ehresmann, Ph.V. Demekhin & A. Knie | Fluorescence cascades evoked by resonant interatomic Coulombic decay of inner-valence excited neon clusters | 2017 | Chem. Phys. 482, 165 |
|||
| Abstract: {Resonant interatomic Coulombic decay (RICD) in inner-valence excited neon clusters is observed by a combination of vacuum-ultraviolet (VUV) and UV/visible fluorescence spectroscopy. These ultrafast interatomic electronic processes efficiently quench radiation emission from inner-valence excited clusters. After RICD took place, outer-valence excited clusters relax further by emission of fluorescence. The direct correspondence of the structures observed in the VUV and UV/visible fluorescence signals implies that the final states of the spectator RICD decay by a cascade of radiative decays: First, by the Rydberg-to-Rydberg transitions in the UV/visible spectral range, and then, by the Rydberg-to-valence transition in the VUV range. Our study demonstrates a possibility of detecting interatomic electronic processes by UV/visible fluorescence spectroscopy.} | ||||||
BibTeX:
@article{Hans17,
author = {Hans, A. and Ltaief, L. B. and Förstel, M. and Schmidt, Ph. and Ozga, Ch. and Reiß, Ph. and Holzapfel, X. and Küstner-Wetekam, C. and Wiegandt, F. and Trinter, F. and Hergenhahn, U. and Jahnke, T. and Dörner, R. and Ehresmann, A. and Demekhin, Ph. V. and Knie, A.},
title = {{Fluorescence cascades evoked by resonant interatomic Coulombic decay of inner-valence excited neon clusters}},
journal = {Chem. Phys.},
publisher = {Elsevier},
year = {2017},
volume = {482},
pages = {165},
numpages = {4},
note = {experiment},
doi = {https://doi.org/10.1016/j.chemphys.2016.06.016}
}
|
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| C. Callegari, T. Takanashi, H. Fukuzawa, K. Motomura, D. Iablonskyi, Y. Kumagai, S. Mondal, T. Tachibana, K. Nagaya, T. Nishiyama, K. Matsunami, P. Johnsson, P. Piseri, G. Sansone, A. Dubrouil, M. Reduzzi, P. Carpeggiani, C. Vozzi, M. Devetta, D. Facciala, F. Calegari, M.C. Castrovilli, M. Coreno, M. Alagia, B. Schütte, N. Berrah, O. Plekan, P. Finetti, E. Ferrari, K.C. Prince & K. Ueda | Application of Matched-Filter Concepts to Unbiased Selection of Data in Pump-Probe Experiments with Free Electron Lasers | 2017 | Appl. Sci. 7, 621 |
|||
| Abstract: {Pump-probe experiments are commonly used at Free Electron Lasers (FEL) to elucidate the femtosecond dynamics of atoms, molecules, clusters, liquids and solids. Maximizing the signal-to-noise ratio of the measurements is often a primary need of the experiment, and the aggregation of repeated, rapid, scans of the pump-probe delay is preferable to a single long-lasting scan. The limited availability of beamtime makes it impractical to repeat measurements indiscriminately, and the large, rapid flow of single-shot data that need to be processed and aggregated into a dataset, makes it difficult to assess the quality of a measurement in real time. In post-analysis it is then necessary to devise unbiased criteria to select or reject datasets, and to assign the weight with which they enter the analysis. One such case was the measurement of the lifetime of Intermolecular Coulombic Decay in the weakly-bound neon dimer. We report on the method we used to accomplish this goal for the pump-probe delay scans that constitute the core of the measurement; namely we report on the use of simple auto- and cross-correlation techniques based on the general concept of “matched filter”. We are able to unambiguously assess the signal-to-noise ratio (SNR) of each scan, which then becomes the weight with which a scan enters the average of multiple scans. We also observe a clear gap in the values of SNR, and we discard all the scans below a SNR of 0.45. We are able to generate an average delay scan profile, suitable for further analysis: in our previous work we used it for comparison with theory. Here we argue that the method is sufficiently simple and devoid of human action to be applicable not only in post-analysis, but also for the real-time assessment of the quality of a dataset.} | ||||||
BibTeX:
@article{Callegari17,
author = {Callegari, C. and Takanashi, T. and Fukuzawa, H. and Motomura, K. and Iablonskyi, D. and Kumagai, Y. and Mondal, S. and Tachibana, T. and Nagaya, K. and Nishiyama, T. and Matsunami, K. and Johnsson, P. and Piseri, P. and Sansone, G. and Dubrouil, A. and Reduzzi, M. and Carpeggiani, P. and Vozzi, C. and Devetta, M. and Facciala, D. and Calegari, F. and Castrovilli, M. C. and Coreno, M. and Alagia, M. and Schütte, B. and Berrah, N. and Plekan, O. and Finetti, P. and Ferrari, E. and Prince, K. C. and Ueda, K.},
title = {{Application of Matched-Filter Concepts to Unbiased Selection of Data in Pump-Probe Experiments with Free Electron Lasers}},
journal = {Appl. Sci.},
publisher = {MDPI},
year = {2017},
volume = {7},
pages = {621},
numpages = {9},
note = {experiment},
doi = {https://doi.org/10.3390/app7060621}
}
|
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| R.A. Wilhelm, E. Gruber, J. Schwestka, R. Heller, S. Fascko & F. Aumayr | Neutralization Dynamics of Slow Highly Charged Ions in 2D Materials | 2018 | Appl. Sci. 8, 1050 |
|||
| Abstract: {We review experimental and theoretical work on the interaction of slow highly charged ions with two-dimensional materials. Earlier work in the field is summarized and more recent studies on 1 nm thick amorphous carbon nanomembranes and freestanding single layer graphene by the authors are reviewed. To explain the findings, models for energy loss determination as well as qualitative model descriptions for the observed ultrafast neutralization dynamics are discussed. The results shown in this paper will be put into context with findings of nanostructure formation on two-dimensional materials, both freestanding and on substrate, as well as on surfaces of bulk insulators.} | ||||||
BibTeX:
@article{Wilhelm18,
author = {Wilhelm, R. A. and Gruber, E. and Schwestka, J. and Heller, R. and Fascko, S. and Aumayr, F.},
title = {{Neutralization Dynamics of Slow Highly Charged Ions in 2D Materials}},
journal = {Appl. Sci.},
publisher = {MDPI},
year = {2018},
volume = {8},
pages = {1050},
numpages = {16},
note = {experiment},
doi = {https://doi.org/10.3390/app8071050}
}
|
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| P. Yu. Serdobintsev, A.S. Melnikov, A.A. Pastor, N.A. Timofeev & M.A. Khodorkovskiy | Relaxation times measurement in single and multiply excited xenon clusters | 2018 | J. Chem. Phys. 148, 194301 |
|||
| Abstract: {Direct measurement of the rates of nonradiative relaxation processes in electronically excited xenon clusters was carried out. The clusters were created in a pulsed supersonic beam and two-photon excited by femtosecond laser pulses with a wavelength of 263 nm. The measurements were performed using the pump-probe method and electron spectroscopy. It is shown that relaxation of light clusters XeN (N < 15) predominantly occurs by desorption of excited xenon atoms with a characteristic time constant of 3 ps. Heavier electronically excited clusters (N > 10) vibrationally relax to the lowest electronically excited state at a rate of about 0.075 eV/ps. Multiply excited clusters are deactivated via energy exchange between excited centers with the ionization of one of them. The production of electrons in this process occurs with a delay of ∼4 ps from the pump pulse, and the process is completed in 10 ps.} | ||||||
BibTeX:
@article{Serdobintsev18,
author = {Serdobintsev, P. Yu. and Melnikov, A. S. and Pastor, A. A. and Timofeev, N. A. and Khodorkovskiy, M. A.},
title = {{Relaxation times measurement in single and multiply excited xenon clusters}},
journal = {J. Chem. Phys.},
publisher = {AIP},
year = {2018},
volume = {148},
pages = {194301},
numpages = {7},
note = {experiment},
doi = {https://doi.org/10.1063/1.5025274}
}
|
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| B. Oostenrijk, N. Walsh, J. Laksman, E.P. Mansson, Ch. Grunewald, S.L. Sorensen & M. Gisselbrecht | The role of charge and proton transfer in fragmentation of hydrogen-bonded nanosystems: the breakup of ammonia clusters upon single photon multi-ionization | 2018 | Phys. Chem. Chem. Phys. 20, 932 |
|||
| Abstract: {The charge and proton dynamics in hydrogen-bonded networks are investigated using ammonia as a model system. The fragmentation dynamics of medium-sized clusters (1-2 nm) upon single photon multi-ionization is studied, by analyzing the momenta of small ionic fragments. The observed fragmentation pattern of the doubly- and triply-charged clusters reveals a spatial anisotropy of emission between fragments (back-to-back). Protonated fragments exhibit a distinct kinematic correlation, indicating a delay between ionization and fragmentation (fission). The different kinematics observed for channels containing protonated and unprotonated species provides possible insights into the prime mechanisms of charge and proton transfer, as well as proton hopping, in such a nanoscale system.} | ||||||
BibTeX:
@article{Oostenrijk18,
author = {Oostenrijk, B. and Walsh, N. and Laksman, J. and Mansson, E. P. and Grunewald, Ch. and Sorensen, S. L. and Gisselbrecht, M.},
title = {{The role of charge and proton transfer in fragmentation of hydrogen-bonded nanosystems: the breakup of ammonia clusters upon single photon multi-ionization}},
journal = {Phys. Chem. Chem. Phys.},
publisher = {RSC},
year = {2018},
volume = {20},
pages = {932},
numpages = {9},
note = {experiment},
doi = {https://doi.org/10.1039/C7CP06688K}
}
|
||||||
| L.B. Ltaief, A. Hans, Ph. Schmidt, X. Holzapfel, F. Wiegandt, Ph. Reiss, C. Küstner-Wetekam, T. Jahnke, R. Dörner, A. Knie & A. Ehresmann | VUV photon emission from Ne clusters of varying sizes following photon and photoelectron excitations | 2018 | J. Phys. B: At. Mol. Opt. Phys. 51, 065002 |
|||
| Abstract: {Vacuum ultraviolet (VUV) fluorescence emission from neon clusters of different sizes is investigated after excitation with photons of energies between 34 and 49 eV, i.e. near and far below the Ne 2s-electron photoionization threshold. Undispersed VUV fluorescence (<120 nm) excitation functions in the Ne 2s-regime display a series of distinct features attributed to 2s → np resonant cluster excitations with subsequent cluster-specific decays. Features connected with resonant interatomic Coulombic decay are visible for all cluster sizes. For larger clusters they appear to be less prominent due to additional emissions. This emission has a threshold energy of 35.8 eV and increases with exciting-photon energy. It also increases with increasing cluster size and is interpreted as being caused by inelastically scattered 2p-photoelectrons (photoelectron impact induced luminescence).} | ||||||
BibTeX:
@article{Ltaief18,
author = {Ltaief, L. B. and Hans, A. and Schmidt, Ph. and Holzapfel, X. and Wiegandt, F. and Reiss, Ph. and Küstner-Wetekam, C. and Jahnke, T. and Dörner, R. and Knie, A. and Ehresmann, A.},
title = {{VUV photon emission from Ne clusters of varying sizes following photon and photoelectron excitations}},
journal = {J. Phys. B: At. Mol. Opt. Phys.},
publisher = {IOP},
year = {2018},
volume = {51},
issue = {6},
pages = {065002},
numpages = {6},
note = {experiment},
doi = {https://doi.org/10.1088/1361-6455/aaac1f}
}
|
||||||
| E. Evlyukhin, E. Kim, D. Goldberger, P. Cifligu, S. Schyck, Ph.F. Weck & M. Pravica | High-pressure-assisted X-ray-induced damage as a new route for chemical and structural synthesis | 2018 | Phys. Chem. Chem. Phys. 20, 18949 |
|||
| Abstract: {X-ray induced damage has been known for decades and has largely been viewed as a tremendous nuisance. We, on the other hand, harness the highly ionizing and penetrating properties of hard X-rays to initiate novel decomposition and synthetic chemistry. Here, we show that powdered cesium oxalate monohydrate pressurized to ≤0.5 GPa and irradiated with X-rays of energies near the cesium K-edge undergoes molecular and structural transformations with one of the final products exhibiting a new type of bcc crystal structure that has previously not been observed. Additionally, based on cascades of ultrafast electronic relaxation steps triggered by the absorption of one X-ray photon, we propose a model explaining the X-ray induced damage of multitype bounded matter. As X-rays are ubiquitous, these results show promise in the preparation of novel compounds and novel structures that are inaccessible via conventional methods. They may offer insight into the formation of complex organic compounds in outer space.} | ||||||
BibTeX:
@article{Evlyukhin18,
author = {Evlyukhin, E. and Kim, E. and Goldberger, D. and Cifligu, P. and Schyck, S. and Weck, Ph. F. and Pravica, M.},
title = {{High-pressure-assisted X-ray-induced damage as a new route for chemical and structural synthesis}},
journal = {Phys. Chem. Chem. Phys.},
publisher = {RSC},
year = {2018},
volume = {20},
pages = {18949},
numpages = {8},
note = {experiment},
doi = {https://doi.org/10.1039/C8CP02119H}
}
|
||||||
| J. Schwestka, A. Niggas, S. Creutzburg, R. Kozubek, R. Heller, M. Schleberger, R.A. Wilhelm & F. Aumayr | Charge-Exchange-Driven Low-Energy Electron Splash Induced by Heavy Ion Impact on Condensed Matter | 2019 | J. Phys. Chem. Lett. 10, 4805 |
|||
| Abstract: {Low-energy electrons (LEEs) are of great relevance for ion-induced radiation damage in cells and genes. We show that charge exchange of ions leads to LEE emission upon impact on condensed matter. By using a graphene monolayer as a simple model system for condensed organic matter and utilizing slow highly charged ions (HCIs) as projectiles, we highlight the importance of charge exchange alone for LEE emission. We find a large number of ejected electrons resulting from individual ion impacts (up to 80 electrons/ion for Xe40+). More than 90% of emitted electrons have energies well below 15 eV. This “splash” of low-energy electrons is interpreted as the consequence of ion deexcitation via an interatomic Coulombic decay (ICD) process.} | ||||||
BibTeX:
@article{Schwestka19,
author = {Schwestka, J. and Niggas, A. and Creutzburg, S. and Kozubek, R. and Heller, R. and Schleberger, M. and Wilhelm, R. A. and Aumayr, F.},
title = {{Charge-Exchange-Driven Low-Energy Electron Splash Induced by Heavy Ion Impact on Condensed Matter}},
journal = {J. Phys. Chem. Lett.},
publisher = {American Chemical Society},
year = {2019},
volume = {10},
pages = {4805},
numpages = {7},
note = {experiment},
doi = {https://doi.org/10.1021/acs.jpclett.9b01774}
}
|
||||||
| G. Schmid, K. Schnorr, S. Augustin, S. Meister, H. Lindenblatt, F. Trost, Y. Liu, M. Braune, R. Treusch, C.D. Schröter, T. Pfeifer & R. Moshammer | Reaction microscope endstation at FLASH2 | 2019 | J. Synchrotron Rad. 26, 854 |
|||
| Abstract: {A reaction microscope dedicated to multi-particle coincidence spectroscopy on gas-phase samples is installed at beamline FL26 of the free-electron laser FLASH2 in Hamburg. The main goals of the instrument are to follow the dynamics of atoms, molecules and small clusters on their natural time-scale and to study non-linear light-matter interaction with such systems. To this end, the reaction microscope is combined with an in-line extreme-ultraviolet (XUV) split-delay and focusing optics, which allows time-resolved XUV-XUV pump-probe spectroscopy to be performed.} | ||||||
BibTeX:
@article{Schmid19,
author = {Schmid, G. and Schnorr, K. and Augustin, S. and Meister, S. and Lindenblatt, H. and Trost, F. and Liu, Y. and Braune, M. and Treusch, R. and Schröter, C. D. and Pfeifer, T. and Moshammer, R.},
title = {{Reaction microscope endstation at FLASH2}},
journal = {J. Synchrotron Rad.},
year = {2019},
volume = {26},
issue = {3},
pages = {854},
numpages = {14},
note = {experiment},
doi = {https://doi.org/10.1107/S1600577519002236}
}
|
||||||
| C.-M. Saak, I. Unger, B. Brena, C. Caleman & O. Björneholm | Site-specific X-ray induced dynamics in liquid methanol | 2019 | Phys. Chem. Chem. Phys. 21, 15478 |
|||
| Abstract: {Complex chemical and biochemical systems are susceptible to damage from ionising radiation. However, questions remain over the extent to which such damage is influenced by the nature of the surrounding chemical environment, which can consist of both hydrophobic and hydrophilic domains. To gain fundamental insight into the first crucial mechanistic steps of radiation damage in such systems, we need to understand the initial radiation response, i.e. dynamics occurring on the same timescale as electronic relaxation, which occur in these different environments. Amphiphilic molecules contain both hydrophobic and hydrophilic domains, but the propensity for charge delocalisation and proton dynamics to occur in these different domains has been largely unexplored so far. Here, we present carbon and oxygen 1s Auger spectra for liquid methanol, one of the simplest amphiphilic molecules, as well as its fully deuterated equivalent d4-methanol, in order to explore X-ray induced charge delocalisation and proton dynamics occurring on the few femtosecond timescale. Unexpectedly, we find a similar propensity for proton dynamics to occur at both the carbon and oxygen site within the lifetime of the core hole. Our results could serve as a model for decay processes that are likely to occur in other more complex amphiphilic systems.} | ||||||
BibTeX:
@article{Saak19,
author = {Saak, C.-M. and Unger, I. and Brena, B. and Caleman, C. and Björneholm, O.},
title = {{Site-specific X-ray induced dynamics in liquid methanol}},
journal = {Phys. Chem. Chem. Phys.},
publisher = {RSC},
year = {2019},
volume = {21},
pages = {15478},
numpages = {9},
note = {experiment},
doi = {https://doi.org/10.1039/C9CP02063B}
}
|
||||||
| A. Niozu, N. Yokono, T. Nishiyama, H. Fukuzawa, T. Sakurazawa, K. Matsuda, T. Takanashi, D. You, Y. Li, T. Ono, Th. Gaumnitz, M. Schöffler, S. Grundmann, S. Wada, P. Carpeggiani, W.Q. Xu, X.J. Liu, S. Owada, K. Tono, T. Togashi, M. Yabashi, N.V. Kryzhevoi, K. Gokhberg, A.I. Kuleff, L.S. Cederbaum, K. Ueda & K. Nagaya | Electron spectroscopic study of nanoplasma formation triggered by intense soft x-ray pulses | 2019 | J. Chem. Phys. 151, 184305 |
|||
| Abstract: {Using electron spectroscopy, we investigated the nanoplasma formation process generated in xenon clusters by intense soft x-ray free electron laser (FEL) pulses. We found clear FEL intensity dependence of electron spectra. Multistep ionization and subsequent ionization frustration features are evident for the low FEL-intensity region, and the thermal electron emission emerges at the high FEL intensity. The present FEL intensity dependence of the electron spectra is well addressed by the frustration parameter introduced by Arbeiter and Fennel [New J. Phys. 13, 053022 (2011)]} | ||||||
BibTeX:
@article{Niozu19,
author = {Niozu, A. and Yokono, N. and Nishiyama, T. and Fukuzawa, H. and Sakurazawa, T. and Matsuda, K. and Takanashi, T. and You, D. and Li, Y. and Ono, T. and Gaumnitz, Th. and Schöffler, M. and Grundmann, S. and Wada, S. and Carpeggiani, P. and Xu, W. Q. and Liu, X. J. and Owada, S. and Tono, K. and Togashi, T. and Yabashi, M. and Kryzhevoi, N. V. and Gokhberg, K. and Kuleff, A. I. and Cederbaum, L. S. and Ueda, K. and Nagaya, K.},
title = {{Electron spectroscopic study of nanoplasma formation triggered by intense soft x-ray pulses}},
journal = {J. Chem. Phys.},
publisher = {AIP},
year = {2019},
volume = {151},
pages = {184305},
numpages = {6},
note = {experiment},
doi = {https://doi.org/10.1063/1.5115053}
}
|
||||||
| A. Müller, M. Martins, A.L.D. Kilcoyne, R.A. Phaneuf, J. Hellhund, A. Borovik Jr., K. Holste, S. Bari, T. Buhr, S. Klumpp, A. Perry-Sassmannshausen, S. Reinwardt, S. Ricz, K. Schubert & S. Schippers | Photoionization and photofragmentation of singly charged positive and negative Sc3N@C80 endohedral fullerene ions | 2019 | Phys. Rev. A 99, 063401 |
|||
| Abstract: {Photoprocesses of the endohedral fullerene ions Sc3N@C80+ and Sc3N@C80- in the gas phase have been investigated in the photon energy ranges 30-50 eV and 280-420 eV. Single and double ionization as well as single ionization accompanied by the release of a C2 dimer were observed as a function of the photon energy for the positive parent ion and double detachment was measured for the negative parent ion. The emphasis of the experiments was on the specific effects of the encapsulated trimetallic nitride cluster Sc3N on the observed reactions. Clear evidence of photoexcitation near the Sc L edge is obtained with the dominating contributions visible in the one- and two-electron-removal channels. K-vacancy production in the encapsulated central nitrogen atom is seen in the single ionization of Sc3N@C80+ but is much less pronounced in the photoionization-with-fragmentation channel. Comparison of the cross sections near the carbon K edge with the corresponding channels measured previously in the photoionization of Lu3N@C80+ reveal strong similarities. Previously predicted sharp resonance features in the ionization of Sc3N@C80+ ions below the Sc M edge are not confirmed. The experiments are accompanied by quantum-chemistry calculations in the Hartree-Fock approximation and by model calculations employing density functional theory (DFT).} | ||||||
BibTeX:
@article{Mueller19,
author = {Müller, A. and Martins, M. and Kilcoyne, A.L.D. and Phaneuf, R. A. and Hellhund, J. and Borovik Jr., A. and Holste, K. and Bari, S. and Buhr, T. and Klumpp, S. and Perry-Sassmannshausen, A. and Reinwardt, S. and Ricz, S. and Schubert, K. and and Schippers, S.},
title = {{Photoionization and photofragmentation of singly charged positive and negative Sc3N@C80 endohedral fullerene ions}},
journal = {Phys. Rev. A},
publisher = {American Physical Society},
year = {2019},
volume = {99},
issue = {6},
pages = {063401},
numpages = {16},
note = {experiment},
doi = {https://doi.org/10.1103/PhysRevA.99.063401}
}
|
||||||
| A.C. LaForge, M. Shcherbinin, F. Stienkemeier, R. Richter, R. Moshammer, T. Pfeifer & M. Mudrich | Highly efficient double ionization of mixed alkali dimers by intermolecular Coulombic decay | 2019 | Nat. Phys. 15, 247 |
|||
| Abstract: {As opposed to purely molecular systems where electron dynamics proceed only through intramolecular processes, weakly bound complexes such as He droplets offer an environment where local excitations can interact with neighbouring embedded molecules leading to new intermolecular relaxation mechanisms. Here, we report on a new decay mechanism leading to the double ionization of alkali dimers attached to He droplets by intermolecular energy transfer. From the electron spectra, the process is similar to the well-known shake-off mechanism observed in double Auger decay and single-photon double ionization, however, in this case, the process is dominant, occurring with efficiencies equal to, or greater than, single ionization by energy transfer. Although an alkali dimer attached to a He droplet is a model case, the decay mechanism is relevant for any system where the excitation energy of one constituent exceeds the double ionization potential of another neighbouring molecule. The process is, in particular, relevant for biological systems, where radicals and slow electrons are known to cause radiation damage.} | ||||||
BibTeX:
@article{LaForge19,
author = {LaForge, A. C. and Shcherbinin, M. and Stienkemeier, F. and Richter, R. and Moshammer, R. and Pfeifer, T. and Mudrich, M. },
title = {{Highly efficient double ionization of mixed alkali dimers by intermolecular Coulombic decay}},
journal = {Nat. Phys.},
publisher = {Nature Research},
year = {2019},
volume = {15},
pages = {247},
numpages = {5},
note = {experiment},
doi = {https://doi.org/10.1038/s41567-018-0376-5}
}
|
||||||
| M. Kelbg, M. Zabel, B. Krebs, L. Kazak, K.-H. Meiwes-Broer & J. Tiggesbäumker | Auger emission from the Coulomb explosion of helium nanoplasmas | 2019 | J. Chem. Phys. 150, 204302 |
|||
| Abstract: {The long-time correlated decay dynamics of strong-field exposed helium nanodroplets is studied by means of photoelectron spectroscopy. As a result of the adiabatic expansion of the laser-produced, fully inner-ionized nanoplasma, delocalized electrons in the deep confining mean field potential are shifted towards the vacuum level. Meanwhile, part of the electrons localize in bound levels of the helium ions. The simple hydrogenlike electronic structure of He+ results in clear signatures in the experimentally observed photoelectron spectra, which can be traced back to bound-free and bound-bound transitions. Auger electron emission takes place as a result of the transfer of transition energy to weakly bound electrons in the quasifree electron band. Hence, the spatial and temporal development of the nanoplasma cloud is encoded in the experimental spectra, whereas the electronic properties of He+ help resolve the different contributions.} | ||||||
BibTeX:
@article{Kelbg19,
author = {Kelbg, M. and Zabel, M. and Krebs, B. and Kazak, L. and Meiwes-Broer, K.-H. and Tiggesbäumker, J.},
title = {{Auger emission from the Coulomb explosion of helium nanoplasmas}},
journal = {J. Chem. Phys.},
publisher = {AIP},
year = {2019},
volume = {150},
pages = {204302},
numpages = {6},
note = {experiment},
doi = {https://doi.org/10.1063/1.5089943}
}
|
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| W. Iskandar, A.S. Gatton, B. Gaire, F.P. Sturm, K.A. Larsen, E.G. Champenois, N. Shivaram, A. Moradmand, J.B. Williams, B. Berry, T. Severt, I. Ben-Itzhak, D. Metz, H. Sann, M. Weller, M. Schöffler, T. Jahnke, R. Dörner, D. Slaughter & Th. Weber | Tracing intermolecular Coulombic decay of carbon-dioxide dimers and oxygen dimers after valence photoionization | 2019 | Phys. Rev. A 99, 043414 |
|||
| Abstract: {We have conducted an experimental study on the photo double ionization (PDI) of carbon-dioxide dimers at photon energies of 37 and 55 eV and oxygen dimers at photon energies of 38, 41.5, and 46 eV, while focusing on the dissociation dynamics upon single-photon absorption. The investigation was performed by applying the cold-target recoil-ion momentum spectroscopy method in order to collect and record the three-dimensional momenta of the ionic fragments and emitted electrons from the dissociating dimer in coincidence. The kinetic-energy release upon fragmentation and the electron angular distributions in the laboratory and body-fixed frames, as well as the relative electron-electron emission angle, show unambiguous experimental evidence of intermolecular Coulombic decay (ICD) in carbon-dioxide dimers upon photoionization below and above the double-ionization threshold of CO2 monomers. The PDI of oxygen dimers is less conclusive and shows contributions from ICD and knock-off ionization mechanisms. As for atomic dimers, the present results reveal that ICD in CO2 dimers after valence PDI can also serve as a source for low-energy electrons, known to be very relevant in biological systems, cells, and tissues.} | ||||||
BibTeX:
@article{Iskandar19,
author = {Iskandar, W. and Gatton, A. S. and Gaire, B. and Sturm, F. P. and Larsen, K. A. and Champenois, E. G. and Shivaram, N. and Moradmand, A. and Williams, J. B. and Berry, B. and Severt, T. and Ben-Itzhak, I. and Metz, D. and Sann, H. and Weller, M. and Schöffler, M. and Jahnke, T. and Dörner, R. and Slaughter, D. and Weber, Th.},
title = {{Tracing intermolecular Coulombic decay of carbon-dioxide dimers and oxygen dimers after valence photoionization}},
journal = {Phys. Rev. A},
publisher = {American Physical Society},
year = {2019},
volume = {99},
issue = {4},
pages = {043414},
numpages = {13},
note = {experiment},
doi = {https://doi.org/10.1103/PhysRevA.99.043414}
}
|
||||||
| A. Hans, Ph. Schmidt, Ch. Ozga, C. Richter, H. Otto, X. Holzapfel, G. Hartmann, A. Ehresmann, U. Hergenhahn & A. Knie | Efficient Fluorescence Quenching by Distant Production of a Free Electron | 2019 | J. Phys. Chem. Lett. 10, 1078 |
|||
| Abstract: {Energy and charge transfer processes play an important role in many fundamental reactions in chemistry, biochemistry, and even technology. If an entity that is part of a larger system is photoexcited, its energy will dissipate, for example, by rearrangement of electron density in a large molecule or by photon emission (fluorescence). Here, we report the experimental observation of free electrons from a heterogeneous van der Waals cluster, in which some sites act as electron emitters receiving their energy efficiently from other “antenna” sites that are resonantly excited in the UV range. By complementing electron spectroscopy with fluorescence detection, we can directly observe that electron emission via this mechanism completely quenches fluorescence once the channel opens. We suggest this mechanism to be important for both quenching of fluorescence as well as resonantly enhancing free electron production in a variety of systems.} | ||||||
BibTeX:
@article{Hans19,
author = {Hans, A. and Schmidt, Ph. and Ozga, Ch. and Richter, C. and Otto, H. and Holzapfel, X. and Hartmann, G. and Ehresmann, A. and Hergenhahn, U. and Knie, A.},
title = {{Efficient Fluorescence Quenching by Distant Production of a Free Electron}},
journal = {J. Phys. Chem. Lett.},
publisher = {American Chemical Society},
year = {2019},
volume = {10},
pages = {1078},
numpages = {5},
note = {experiment},
doi = {https://doi.org/10.1021/acs.jpclett.9b00124}
}
|
||||||
| H. Fukuzawa, Y. Li, D. You, Y. Sakakibara, S. Yamada, Y. Ito, T. Takanashi, M. Oura, N. Saito & K. Ueda | Low-energy-electron production after 2p ionization of argon clusters | 2019 | Phys. Rev. A 99, 042505 |
|||
| Abstract: {Irradiation of matter with x rays causes inner-shell ionization of atoms and molecules, followed by subsequent electronic relaxation leading to production of low-energy electrons. In this study we investigate the process of low-energy-electron production in Ar clusters by electron-ion multiple coincidence measurements. In addition to photoelectrons, low-energy electrons are observed after 2p ionization of argon clusters. We find that low-energy-electron production increases when the energy of photoelectrons exceeds the ionization potential of Ar. We experimentally identify the low-energy electrons produced by interatomic electronic decay processes and inelastic scattering of the photoelectrons and Auger electrons with the surrounding Ar atoms.} | ||||||
BibTeX:
@article{Fukuzawa19_a,
author = {Fukuzawa, H. and Li, Y. and You, D. and Sakakibara, Y. and Yamada, S. and Ito, Y. and Takanashi, T. and Oura, M. and Saito, N. and Ueda, K.},
title = {{Low-energy-electron production after 2p ionization of argon clusters}},
journal = {Phys. Rev. A},
publisher = {American Physical Society},
year = {2019},
volume = {99},
issue = {4},
pages = {042505},
numpages = {7},
note = {experiment},
doi = {https://doi.org/10.1103/PhysRevA.99.042505}
}
|
||||||
| I. Balmaev, P. Serdobintsev, A. Melnikov, A. Pastor & M. Khodorkovskiy | Energy transfer in heteronuclear rare gas clusters under multiphoton excitation and ionization | 2019 | J. Phys.: Conf. Ser. 1410, 012135 |
|||
| Abstract: {The ionization processes of the ArM, XeN and XeNArM clusters in a supersonic beam with multiphoton excitation were studied. The third 263 nm harmonics of a femtosecond Ti : sapphire laser were used for excitation and ionization. Kinetic energy spectra of photoelectrons has been recorded by a magnetic bottle time-of-flight electron spectrometer. Analysis of the electronic spectra of multiphoton ionization of clusters shows that, in heteronuclear clusters, the transfer of excitation energy between xenon and argon atoms plays a significant role in ionization.} | ||||||
BibTeX:
@proceedings{Balmaev19,
author = {Balmaev, I. and Serdobintsev, P. and Melnikov, A. and Pastor, A. and Khodorkovskiy, M.},
title = {{Energy transfer in heteronuclear rare gas clusters under multiphoton excitation and ionization}},
journal = {J. Phys.: Conf. Ser.},
series= {6th International School and Conference “Saint Petersburg OPEN 2019”: Optoelectronics, Photonics, Engineering and Nanostructures},
publisher = {IOP},
year = {2019},
volume = {1410},
pages = {012135},
numpages = {5},
note = {experiment},
doi = {https://doi.org/10.1088/1742-6596/1410/1/012135}
}
|
||||||
| P. Zhang, C. Perry, T.T. Luu & H.J. Wörner | Observation of intermolecular Coulombic decay in liquid water | 2020 | OSA Technical Digest , M3B.4 |
|||
| Abstract: {Intermolecular Coulombic decay has been observed in liquid water for the first time. This was achieved using monochromatized high-harmonic radiation coupled to a liquid microjet and an electron-electron coincidence spectrometer.} | ||||||
BibTeX:
@proceedings{Zhang20,
author = {Zhang, P. and Perry, C. and Luu, T. T. and Wörner, H. J.},
title = {{Observation of intermolecular Coulombic decay in liquid water}},
journal = {OSA Technical Digest},
series= {The 22nd International Conference on Ultrafast Phenomena 2020},
publisher = {OSA},
year = {2020},
pages = {M3B.4},
numpages = {3},
note = {experiment},
doi = {https://doi.org/10.1364/UP.2020.M3B.4}
}
|
||||||
| S. Yan, X.L. Zhu, S.F. Zhang, D.M. Zhao, P. Zhang, B. Wei & X. Ma | Enhanced damage induced by secondary high-energy electrons | 2020 | Phys. Rev. A 102, 032809 |
|||
| Abstract: {A new kind of radiotherapy scheme based on the resonant Auger–interatomic Coulombic decay mechanism (RA ICD) was proposed in the work of Gokhberg et al. [Nature 505, 661 (2014)], which may effectively reduce the overall radiation dose in traditional x-ray radiotherapy. An electron produced in this scheme carries most of the energy of the primary x-ray photon. Through the present experiment using an energetic electron impact on a NeAr dimer, we demonstrate that three processes, namely, the interatomic Coulombic decay triggered by a Ne 2s electron ionization, ICD triggered by Ar+*(3p4nl ≥ 5d), and charge transfer in the Ar2+Ne ion, can take place and enhance the yields of slow electrons and ions. Therefore, energetic secondary electrons make the x-ray RA ICD scheme more toxic in radiotherapy.} | ||||||
BibTeX:
@article{Yan20,
author = {Yan, S. and Zhu, X. L. and Zhang, S. F. and Zhao, D. M. and Zhang, P. and Wei, B. and Ma, X.},
title = {{Enhanced damage induced by secondary high-energy electrons}},
journal = {Phys. Rev. A},
publisher = {American Physical Society},
year = {2020},
volume = {102},
issue = {3},
pages = {032809},
numpages = {6},
note = {experiment},
doi = {https://doi.org/10.1103/PhysRevA.102.032809}
}
|
||||||
| C.-M. Saak, I. Unger, G. Gopakumar, C. Caleman & O. Björneholm | Temperature Dependence of X-Ray Induced Auger Processes in Liquid Water | 2020 | J. Phys. Chem. Lett. 11, 2497 |
|||
| Abstract: {Auger spectroscopy has previously been used to study changes in the hydrogen bond network in liquid water, but to the best of our knowledge it hasn't been used to track such changes as a function of temperature. We show Auger spectroscopy to reflect the weakening of the hydrogen bond network upon heating. This shows that the radiation response of water, i.e. the relative propensity of the different processes occurring after radiation exposure, including femtosecond proton dynamics, depends on the temperature of the system. This proof-of-principle study further demonstrates the suitability of the technique to help elucidate information on the intermolecular structure of liquids such as water, opening the door to further temperature-dependent studies.} | ||||||
BibTeX:
@article{Saak20_b,
author = {Saak, C.-M. and Unger, I. and Gopakumar, G. and Caleman, C. and Björneholm, O.},
title = {{Temperature Dependence of X-Ray Induced Auger Processes in Liquid Water}},
journal = {J. Phys. Chem. Lett.},
publisher = {American Chemical Society},
year = {2020},
volume = {11},
pages = {2497},
numpages = {5},
note = {experiment},
doi = {https://doi.org/10.1021/acs.jpclett.0c00158}
}
|
||||||
| C.-M. Saak, C. Richter, I. Unger, M. Mucke, Ch. Nicolas, U. Hergenhahn, C. Caleman, M. Huttula, M. Patanen & O. Björneholm | Proton dynamics in molecular solvent clusters as an indicator for hydrogen bond network strength in confined geometries | 2020 | Phys. Chem. Chem. Phys. 22, 3264 |
|||
| Abstract: {Hydrogen bonding leads to the formation of strong, extended intermolecular networks in molecular liquids such as water. However, it is less well-known how robust the network is to environments in which surface formation or confinement effects become prominent, such as in clusters or droplets. Such systems provide a useful way to probe the robustness of the network, since the degree of confinement can be tuned by altering the cluster size, changing both the surface-to-volume ratio and the radius of curvature. To explore the formation of hydrogen bond networks in confined geometries, here we present O 1s Auger spectra of small and large clusters of water, methanol, and dimethyl ether, as well as their deuterated equivalents. The Auger spectra of the clusters and the corresponding macroscopic liquids are compared and evaluated for an isotope effect, which is due to proton dynamics within the lifetime of the core hole (proton-transfer-mediated charge-separation, PTM-CS), and can be linked to the formation of a hydrogen bond network in the system. An isotope effect is observed in water and methanol but not for dimethyl ether, which cannot donate a hydrogen bond at its oxygen site. The isotope effect, and therefore the strength of the hydrogen bond network, is more pronounced in water than in methanol. Its value depends on the average size of the cluster, indicating that confinement effects change proton dynamics in the core ionised excited state.} | ||||||
BibTeX:
@article{Saak20_a,
author = {Saak, C.-M. and Richter, C. and Unger, I. and Mucke, M. and Nicolas, Ch. and Hergenhahn, U. and Caleman, C. and Huttula, M. and Patanen, M. and Björneholm, O.},
title = {{Proton dynamics in molecular solvent clusters as an indicator for hydrogen bond network strength in confined geometries}},
journal = {Phys. Chem. Chem. Phys.},
publisher = {RSC},
year = {2020},
volume = {22},
pages = {3264},
numpages = {9},
note = {experiment},
doi = {https://doi.org/10.1039/C9CP06661F}
}
|
||||||
| R. Obaid, H. Xiong, S. Augustin, K. Schnorr, U. Ablikim, A. Battistoni, T.J.A. Wolf, R. Bilodeau, T. Osipov, K. Gokhberg, D. Rolles, A.C. LaForge & N. Berrah | Intermolecular Coulombic Decay in Endohedral Fullerene at the 4d -> 4f Resonance | 2020 | Phys. Rev. Lett. 124, 113002 |
|||
| Abstract: {Intermolecular processes offer unique decay mechanisms for complex systems to internally relax. Here, we report the observation of an intermolecular Coulombic decay channel in an endohedral fullerene, a holmium nitride complex (Ho3N) embedded within a C80 fullerene, between neighboring holmium ions, and between the holmium complex and the carbon cage. By measuring the ions and the electrons in coincidence after XUV photoabsorption, we can isolate the different decay channels, which are found to be more prevalent relative to intra-atomic Auger decay.} | ||||||
BibTeX:
@article{Obaid20,
author = {Obaid, R. and Xiong, H. and Augustin, S. and Schnorr, K. and Ablikim, U. and Battistoni, A. and Wolf, T.J.A. and Bilodeau, R. and Osipov, T. and Gokhberg, K. and Rolles, D. and LaForge, A. C. and Berrah, N.},
title = {{Intermolecular Coulombic Decay in Endohedral Fullerene at the 4d -> 4f Resonance}},
journal = {Phys. Rev. Lett.},
publisher = {American Physical Society},
year = {2020},
volume = {124},
issue = {11},
pages = {113002},
numpages = {6},
note = {experiment},
doi = {https://doi.org/10.1103/PhysRevLett.124.113002}
}
|
||||||
| S. Nagaoka, O. Takahashi & Y. Hikosaka | Site-specificity reduction during Auger decay following Si:2p photoionization in Cl3SiSi(CH3)3 vapor: An interatomic-Coulombic-decay-like process | 2020 | Chem. Phys. 534, 110756 |
|||
| Abstract: {L23VV Auger decays caused by Si:2p core-level photoionization in Cl3SiSi(CH3)3 vapor have been studied by means of photoelectron Auger-electron coincidence spectroscopy. Upon the Si:2p photoionization, Cl3Si(CH2)nSi(CH3)3 (n = 0–2) shows two core-photoelectron emissions that are distinguishable by the silicon site. Cl3SiCH2CH2Si(CH3)3 (n = 2) and so forth, which have a long inter-site bridge, remember the initially core-ionized silicon-site and show site-specific fragmentation. In contrast, Cl3SiSi(CH3)3, which has direct Si—Si bonding (n = 0), forgets the initially core-ionized silicon-site and shows negligible site-specificity in the final fragmentation stage. A reduction of the site specificity in Cl3SiSi(CH3)3 starts during a Si:L23VV Auger decay and its reduction process can be explained in terms of an interatomic-Coulombic-decay-like mechanism. Another site-specificity reduction, caused by inter-site energy randomization, occurs after every Si:L23VV Auger decay.} | ||||||
BibTeX:
@article{Nagaoka20,
author = {Nagaoka, S. and Takahashi, O. and Hikosaka, Y.},
title = {{Site-specificity reduction during Auger decay following Si:2p photoionization in Cl3SiSi(CH3)3 vapor: An interatomic-Coulombic-decay-like process}},
journal = {Chem. Phys.},
publisher = {Elsevier},
year = {2020},
volume = {534},
pages = {110756},
numpages = {7},
note = {experiment},
doi = {https://doi.org/10.1016/j.chemphys.2020.110756}
}
|
||||||
| K.D. Mudryk, R. Seidel, B. Winter & I. Wilkinson | The electronic structure of the aqueous permanganate ion: aqueous-phase energetics and molecular bonding studied using liquid jet photoelectron spectroscopy | 2020 | Phys. Chem. Chem. Phys. 22, 20311 |
|||
| Abstract: {Permanganate aqueous solutions, MnO4-(aq.), were studied using liquid-micro-jet-based soft X-ray non-resonant and resonant photoelectron spectroscopy to determine valence and core-level binding energies. To identify possible differences in the energetics between the aqueous bulk and the solution–gas interface, non-resonant spectra were recorded at two different probing depths. Similar experiments were performed with different counter ions, Na+ and K+, with the two solutions yielding indistinguishable anion electron binding energies. Our resonant photoelectron spectroscopy measurements, performed near the Mn LII,III- and O K-edges, selectively probed valence charge distributions between the Mn metal center, O ligands, and first solvation shell in the aqueous bulk. Associated resonantly-enhanced solute ionisation signals revealed hybridisation of the solute constituents' atomic orbitals, including the inner valence Mn 3p and O 2s. We identified intermolecular coulombic decay relaxation processes following resonant X-ray excitation of the solute that highlight valence MnO4-(aq.) – H2O(l) electronic couplings. Furthermore, our results allowed us to infer oxidative reorganisation energies of MnO4⋅(aq.) and adiabatic valence ionisation energies of MnO4-(aq.), revealing the Gibbs free energy of oxidation and permitting estimation of the vertical electron affinity of MnO4⋅(aq.). Finally, the Gibbs free energy of hydration of isolated MnO4- was determined. Our results and analysis allowed a near-complete binding-energy-scaled MnO4-(aq.) molecular orbital and a valence energy level diagram to be produced for the MnO4-(aq.)/MnO4⋅(aq.) system. Cumulatively, our mapping of the aqueous-phase electronic structure of MnO4- is expected to contribute to a deeper understanding of the exceptional redox properties of this widely applied aqueous transition-metal complex ion.} | ||||||
BibTeX:
@article{Mudryk20,
author = {Mudryk, K. D. and Seidel, R. and Winter, B. and Wilkinson, I.},
title = {{The electronic structure of the aqueous permanganate ion: aqueous-phase energetics and molecular bonding studied using liquid jet photoelectron spectroscopy}},
journal = {Phys. Chem. Chem. Phys.},
publisher = {RSC},
year = {2020},
volume = {22},
pages = {20311},
numpages = {20},
note = {experiment},
doi = {https://doi.org/10.1039/D0CP04033A}
}
|
||||||
| R. Moshammer & K. Schnorr | Molecular Physics and Gas-Phase Chemistry with Free-Electron Lasers | 2020 | Synchrotron Light Sources and Free-Electron Lasers , 1493 |
|||
| Abstract: {Free-electron lasers provide ultrashort (~10 fs) and extremely intense (~1012 photons/pulse) light pulses over a wavelength regime that spans from soft (10 eV) to hard X-ray energies (15 keV). It is in particular the unrivaled combination of high intensities and short pulse lengths that enables unique, hitherto only partly explored possibilities for molecular physics and photochemistry. Recently performed or anticipated FEL experiments cover widespread topics in this exciting research field: photon-induced reactions in molecular ions relevant for planetary science have been studied, XUV or X-ray pump-probe experiments allow one to trace chemical reactions with atomic spatial and temporal resolution, the dynamical evolution of highly excited molecular states can be monitored on relevant time scales, inner-shell photoelectron spectroscopy has been demonstrated to offer utmost sensitivity for chemical analysis, first diffractive scattering experiments hold the promise to achieve imaging of single molecules in the gas phase, and the very successful concepts applied in femtochemistry with optical and UV laser will certainly be carried over to XUV and X-ray energies in the very near future. Here, an introduction into physical concepts and emerging technologies as well as an overview about recent results is provided. } | ||||||
BibTeX:
@inbook{Moshammer20,
author = {Moshammer, R. and Schnorr, K.},
title = {{Molecular Physics and Gas-Phase Chemistry with Free-Electron Lasers}},
journal = {Synchrotron Light Sources and Free-Electron Lasers},
publisher = {Springer},
year = {2020},
pages = {1493},
numpages = {32},
note = {experiment},
doi = {https://doi.org/10.1007/978-3-030-23201-6_26}
}
|
||||||
| A.R. Milosavljević, K. Jänkälä, M. Lj. Ranković, F. Canon, J. Bozek, Ch. Nicolas & A. Giuliani | Oxygen K-shell spectroscopy of isolated progressively solvated peptide | 2020 | Phys. Chem. Chem. Phys. 22, 12909 |
|||
| Abstract: {Gas-phase near-edge X-ray-absorption fine structure (NEXAFS) action spectroscopy around the oxygen K-edge and mass spectrometry were employed to probe isolated substance P (SP) molecular ions, both bare and progressively solvated with 4 and 11 water molecules. Detailed mass spectra of bare and hydrated precursors are presented for the resonant photon energy of 532 eV that corresponds to O1s → π(amide)* core excitation, triggering resonant Auger decay and fragmentation from the ionized radical molecular system. The fragmentation pattern of doubly protonated SP hydrated with 4 water molecules clearly shows a series of abundant doubly charged backbone fragments, as well as triply charged precursor with small neutral losses, all preserving full water cluster. This is drastically different from the collisional induced dissociation of the hydrated peptide where the water loss is a dominant relaxation process. Moreover, the action NEXAFS obtained from several resolved small backbone fragments revealed increased fragmentation of hydrated SP relative to the bare one, due to a resonant O1s excitation of the attached water molecules. Such unexpected result inspires further experimental developments to investigate possible nonlocal energy transfer from the solvent to the biomolecules within the first solvation shell. The experiment is supported by molecular dynamics and DFT calculations to estimate the intensity of the resonant X-ray absorption of bare and hydrated SP around peptide and water O1s excitation region.} | ||||||
BibTeX:
@article{Milosavljevic20,
author = {Milosavljević, A. R. and Jänkälä, K. and Ranković, M. Lj. and Canon, F. and Bozek, J. and Nicolas, Ch. and Giuliani, A.},
title = {{Oxygen K-shell spectroscopy of isolated progressively solvated peptide}},
journal = {Phys. Chem. Chem. Phys.},
publisher = {RSC},
year = {2020},
volume = {22},
pages = {12909},
numpages = {9},
note = {experiment},
doi = {https://doi.org/10.1039/d0cp00994f}
}
|
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| B.M. Jones, H. Hu, A. Alexsandrov, W. Smith, A.E. Clark, X. Li & T.M. Orlando | Efficient Intermolecular Energy Exchange and Soft Ionization of Water at Nanoplatelet Interfaces | 2020 | J. Phys. Chem. Lett. 11, 10088 |
|||
| Abstract: {X-ray, energetic photon, and electron irradiation can ionize and electronically excite target atoms and molecules. These excitations undergo complicated relaxation and energy-transfer processes that ultimately determine the manifold system responses to the deposited excess energy. In weakly bound gas- and solution-phase samples, intermolecular Coulomb decay (ICD) and electron-transfer-mediated decay (ETMD) can occur with neighboring atoms or molecules, leading to efficient transfer of the excess energy to the surroundings. In ionic solids such as metal oxides, intra- and interatomic Auger decay produces localized final states that lead to lattice damage and typically the removal of cations from the substrate. The relative importance of Auger-stimulated damage (ASD) versus ICD and ETMD in microsolvated nanoparticle interfaces is not known. Though ASD is generally expected, essentially no lattice damage resulting from the ionization and electronic excitation of microsolvated boehmite (AlOOH) nanoplatelets has been detected. Rather efficient energy transfer and soft ionization of interfacial water molecules has been observed. This is likely a general phenomenon at gas–oxyhydroxide nanoparticle interfaces where the density of states of the ionized chemisorbed species significantly overlaps with the core hole states of the solid.} | ||||||
BibTeX:
@article{Jones20,
author = {Jones, B. M. and Hu, H. and Alexsandrov, A. and Smith, W. and Clark, A. E. and Li, X. and Orlando, T. M.},
title = {{Efficient Intermolecular Energy Exchange and Soft Ionization of Water at Nanoplatelet Interfaces}},
journal = {J. Phys. Chem. Lett.},
publisher = {American Chemical Society},
year = {2020},
volume = {11},
issue = {23},
pages = {10088},
numpages = {6},
note = {experiment},
doi = {https://doi.org/10.1021/acs.jpclett.0c02911}
}
|
||||||
| H. Fukuzawa & K. Ueda | X-ray induced ultrafast dynamics in atoms, molecules, and clusters: experimental studies at an X-ray free-electron laser facility SACLA and modelling | 2020 | Adv. Phys. X 5, 1785327 |
|||
| Abstract: {X-ray free electron lasers (XFELs) deliver intense, coherent, femtosecond X-ray laser pulses. They are opening new research fields of studying ultrafast electronic and structural dynamics in various forms of matter and interaction of intense and short X-ray pulses with matter. For such studies, atoms, molecules, and atomic clusters in the gas phase may provide us with ideal platforms as various levels of experimental methods and theory are within reach. Developing experimental setups of electron and ion spectroscopies for gas-phase experiments at SACLA, a low-repetition rate X-ray free electron laser facility in Japan, we have studied the interaction of intense, short X-ray pulses with atoms, molecules, and atomic clusters. Via these experimental investigations and modelling efforts, we gain insight into the interaction of these intense pulses with the single-particle targets and extracted the information about how they are modified during the X-ray pulse duration. We summarize these studies in the present review. The information reported here will be important for any XFEL applications as the scattering signal used to image any targets may be strongly influenced by the XFEL-induced dynamics that occur in the target within the pulse duration.} | ||||||
BibTeX:
@article{Fukuzawa20,
author = {Fukuzawa, H. and Ueda, K.},
title = {{X-ray induced ultrafast dynamics in atoms, molecules, and clusters: experimental studies at an X-ray free-electron laser facility SACLA and modelling}},
journal = {Adv. Phys. X},
publisher = {Taylor & Francis},
year = {2020},
volume = {5},
issue = {1},
pages = {1785327},
numpages = {28},
note = {experiment},
doi = {https://doi.org/10.1080/23746149.2020.1785327}
}
|
||||||
| Ch. Bostedt, T. Gorkhover, D. Rupp & T. Möller | Clusters and Nanocrystals | 2020 | Synchrotron Light Sources and Free-Electron Lasers , 1525 |
|||
| Abstract: {Clusters and nanocrystals constitute intermediates between molecules and condensed matter. Due to their finite size, clusters have a wide spectrum of applications ranging from building blocks for novel materials to model systems for fundamental investigations about light-matter interactions. Short-wavelength radiation from synchrotron radiation sources and free-electron lasers allows the detailed investigation of their geometric, electronic, and magnetic structure as well as dynamical processes. Conversely, clusters can serve as idealized sample systems for the development of new experimental techniques and pioneering experiments with novel x-ray sources. The chapter starts with a brief introduction to cluster physics, followed by a comprehensive overview of research performed at synchrotron light sources on van der Waals, metal, and semiconductor clusters. With the advent of short-wavelength free-electron lasers, a new research field in the x-ray peak intensity regime has opened. Experiments on single clusters, such as x-ray imaging and tracing ultrafast dynamics, now become possible. } | ||||||
BibTeX:
@inbook{Bostedt20,
author = {Bostedt, Ch. and Gorkhover, T. and Rupp, D. and Möller, T.},
title = {{Clusters and Nanocrystals}},
journal = {Synchrotron Light Sources and Free-Electron Lasers},
publisher = {Springer},
year = {2020},
pages = {1525},
numpages = {49},
note = {experiment},
doi = {https://doi.org/10.1007/978-3-030-23201-6_39}
}
|
||||||
| L. Young, E.T. Nienhuis, D. Koulentianos, G. Doumy, A.M. March, S.H. Southworth, S.B. Clark, T.M. Orlando, J.A. LaVerne & C.I. Pearce | Photon-In/Photon-Out X-ray Free-Electron Laser Studies of Radiolysis | 2021 | Appl. Sci. 11, 701 |
|||
| Abstract: {Understanding the origin of reactive species following ionization in aqueous systems is an important aspect of radiation–matter interactions as the initial reactive species lead to production of radicals and subsequent long-term radiation damage. Tunable ultrafast X-ray free-electron pulses provide a new window to probe events occurring on the sub-picosecond timescale, supplementing other methodologies, such as pulse radiolysis, scavenger studies, and stop flow that capture longer timescale chemical phenomena. We review initial work capturing the fastest chemical processes in liquid water radiolysis using optical pump/X-ray probe spectroscopy in the water window and discuss how ultrafast X-ray pump/X-ray probe spectroscopies can examine ionization-induced processes more generally and with better time resolution. Ultimately, these methods will be applied to understanding radiation effects in complex aqueous solutions present in high-level nuclear waste.} | ||||||
BibTeX:
@article{Young21,
author = {Young, L. and Nienhuis, E. T. and Koulentianos, D. and Doumy, G. and March, A. M. and Southworth, S. H. and Clark, S. B. and Orlando, T. M. and LaVerne, J. A. and Pearce, C. I.},
title = {{Photon-In/Photon-Out X-ray Free-Electron Laser Studies of Radiolysis}},
journal = {Appl. Sci.},
publisher = {MDPI},
year = {2021},
volume = {11},
pages = {701},
numpages = {15},
note = {experiment},
doi = {https://doi.org/10.3390/app11020701}
}
|
||||||
| H. Schmidt-Böcking, J. Ullrich, R. Dörner & C.L. Cocke | The COLTRIMS Reaction Microscope - The Spyhole into the Ultrafast Entangled Dynamics of Atomic and Molecular Systems | 2021 | Ann. Phys. 533, 2100134 |
|||
| Abstract: {The COLTRIMS Reaction Microscope C-REMI can image the momentum vectors of all emitted charged fragments in an atomic or molecular reactions similar to the bubble chamber in high energy particle physics. C-REMI can detect fragments with “zero” kinetic energy in an ultrahigh vacuum environment by projecting them with weak electromagnetic fields onto position-sensitive detectors. Geometrically a nearly 4π collection solid angle and a nearly 50% efficiency for a fivefold multi-coincidence can be achieved. Measuring time-of-flight and detector position the momenta of the fragments can be measured with excellent resolution (<0.01 a.u.; see A1 in the Appendix). Thus, multivector correlations in momentum space are measured, which provide insight into the entangled dynamics of atomic and molecular quantum systems. From these vector-correlations phases and energies can be deduced which allow for relative time measurements even in the zeptosecond range. C-REMI provides a “spyhole” into the secrets of ultrafast dynamics of atomic and molecular processes. It is applied today around the globe in numerous research projects in physics and chemistry. The purpose for writing this article is to demonstrate the universal application possibilities of C-REMI, and its high multi-coincidence efficiency and high momentum resolution. This paper will not give a review on all milestone experiments performed with C-REMI.} | ||||||
BibTeX:
@article{SchmidtBoecking21,
author = {Schmidt-Böcking, H. and Ullrich, J. and Dörner, R. and Cocke, C. L.},
title = {{The COLTRIMS Reaction Microscope - The Spyhole into the Ultrafast Entangled Dynamics of Atomic and Molecular Systems}},
journal = {Ann. Phys.},
publisher = {Wiley-VCH},
year = {2021},
volume = {533},
issue = {9},
pages = {2100134},
numpages = {25},
note = {experiment},
doi = {https://doi.org/10.1002/andp.202100134}
}
|
||||||
| R. Michiels, M. Abu-samha, L.B. Madsen, M. Binz, U. Bangert, L. Bruder, R. Duim, A. Wituschek, A.C. LaForge, R.J. Squibb, R. Feifel, C. Callegari, M. Di Fraia, M. Danailov, M. Manfredda, O. Plekan, K.C. Prince, P. Rebernik, M. Zangrando, F. Stienkemeier & M. Mudrich | Enhancement of Above Threshold Ionization in Resonantly Excited Helium Nanodroplets | 2021 | Phys. Rev. Lett. 127, 093201 |
|||
| Abstract: {Clusters and nanodroplets hold the promise of enhancing high-order nonlinear optical effects due to their high local density. However, only moderate enhancement has been demonstrated to date. Here, we report the observation of energetic electrons generated by above-threshold ionization (ATI) of helium (He) nanodroplets which are resonantly excited by ultrashort extreme ultraviolet (XUV) free-electron laser pulses and subsequently ionized by near-infrared (NIR) or near-ultraviolet (UV) pulses. The electron emission due to high-order ATI is enhanced by several orders of magnitude compared with He atoms. The crucial dependence of the ATI intensities with the number of excitations in the droplets suggests a local collective enhancement effect.} | ||||||
BibTeX:
@article{Michiels21,
author = {Michiels, R. and Abu-samha, M. and Madsen, L. B. and Binz, M. and Bangert, U. and Bruder, L. and Duim, R. and Wituschek, A. and LaForge, A. C. and Squibb, R. J. and Feifel, R. and Callegari, C. and Di Fraia, M. and Danailov, M. and Manfredda, M. and Plekan, O. and Prince, K. C. and Rebernik, P. and Zangrando, M. and Stienkemeier, F. and Mudrich, M.},
title = {{Enhancement of Above Threshold Ionization in Resonantly Excited Helium Nanodroplets}},
journal = {Phys. Rev. Lett.},
publisher = {American Physical Society},
year = {2021},
volume = {127},
issue = {9},
pages = {093201},
numpages = {6},
note = {experiment},
doi = {https://doi.org/10.1103/PhysRevLett.127.093201}
}
|
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| T. Jahnke, V. Mergel, O. Jagutzki, A. Czasch, K. Ullmann, R. Ali, V. Frohne, T. Weber, L.P. Schmidt, S. Eckart, M. Schöffler, S. Schößler, S. Voss, A. Landers, D. Fischer, M. Schulz, A. Dorn, L. Spielberger, R. Moshammer, R. Olson, M. Prior, R. Dörner, J. Ullrich, C.L. Cocke & H. Schmidt-Böcking | High-Resolution Momentum Imaging-From Stern's Molecular Beam Method to the COLTRIMS Reaction Microscope | 2021 | Molecular Beams in Physics and Chemistry , 375 |
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| Abstract: {Multi-particle momentum imaging experiments are now capable of providing detailed information on the properties and the dynamics of quantum systems in Atomic, Molecular and Photon (AMO) physics. Historically, Otto Stern can be considered the pioneer of high-resolution momentum measurements of particles moving in a vacuum and he was the first to obtain sub-atomic unit (a.u.) momentum resolution (Schmidt-Böcking et al. in The precision limits in a single-event quantum measurement of electron momentum and position, these proceedings). A major contribution to modern experimental atomic and molecular physics was his so-called molecular beam method, which Stern developed and employed in his experiments. With this method he discovered several fundamental properties of atoms, molecules and nuclei. As corresponding particle detection techniques were lacking during his time, he was only able to observe the averaged footprints of large particle ensembles. Today it is routinely possible to measure the momenta of single particles, because of the tremendous progress in single particle detection and data acquisition electronics. A “state-of-the-art” COLTRIMS reaction microscope can measure, for example, the momenta of several particles ejected in the same quantum process in coincidence with sub-a.u. momentum resolution. Such setups can be used to visualize the dynamics of quantum reactions and image the entangled motion of electrons inside atoms and molecules. This review will briefly summarize Stern's work and then present in longer detail the historic steps of the development of the COLTRIMS reaction microscope. Furthermore, some benchmark results are shown which initially paved the way for a broad acceptance of the COLTRIMS approach. Finally, a small selection of milestone work is presented which has been performed during the last two decades. } | ||||||
BibTeX:
@inbook{Jahnke21,
author = {Jahnke, T. and Mergel, V. and Jagutzki, O. and Czasch, A. and Ullmann, K. and Ali, R. and Frohne, V. and Weber, T. and Schmidt, L. P. and Eckart, S. and Schöffler, M. and Schößler, S. and Voss, S. and Landers, A. and Fischer, D. and Schulz, M. and Dorn, A. and Spielberger, L. and Moshammer, R. and Olson, R. and Prior, M. and Dörner, R. and Ullrich, J. and Cocke, C. L. and Schmidt-Böcking, H.},
title = {{High-Resolution Momentum Imaging-From Stern's Molecular Beam Method to the COLTRIMS Reaction Microscope}},
journal = {Molecular Beams in Physics and Chemistry},
publisher = {Springer},
year = {2021},
pages = {375},
numpages = {67},
note = {experiment},
doi = {https://doi.org/10.1007/978-3-030-63963-1_18}
}
|
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| S. Creutzburg, A. Niggas, D. Weichselbaum, P.L. Grande, F. Aumayr & R.A. Wilhelm | Angle-dependent charge exchange and energy loss of slow highly charged ions in freestanding graphene | 2021 | Phys. Rev. A 104, 042806 |
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| Abstract: {The scattering of ions in solids is accompanied with momentum transfer and electronic excitations resulting in the slowing down of the ion. The amount of energy transferred in a single scattering event depends on the particular trajectory which can be traced back through the scattering angle. Performing scattering angle dependent measurements of slow highly charged Xe ions transmitted through freestanding single-, bi-, and trilayer graphene allows us to determine the charge exchange and energy loss for different minimal interatomic distances. Interestingly, the charge exchange shows an increase with scattering angle by a factor of less than 2, while the energy loss increases by more than a factor of 10 for 3° compared to forward direction. Our results can be compared to a time-dependent potential model and show that determination of the stopping cross section is not straightforward even with angle-dependent data at hand.} | ||||||
BibTeX:
@article{Creutzburg21,
author = {Creutzburg, S. and Niggas, A. and Weichselbaum, D. and Grande, P. L. and Aumayr, F. and Wilhelm, R. A.},
title = {{Angle-dependent charge exchange and energy loss of slow highly charged ions in freestanding graphene}},
journal = {Phys. Rev. A},
publisher = {American Physical Society},
year = {2021},
volume = {104},
issue = {4},
pages = {042806},
numpages = {8},
note = {experiment},
doi = {https://doi.org/10.1103/PhysRevA.104.042806}
}
|
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| J. Zhou, X. Yu, S. Luo, X. Xue, S. Jia, X. Zhang, Y. Zhao, X. Hao, L. He, C. Wang, D. Ding & X. Ren | Triple ionization and fragmentation of benzene trimers following ultrafast intermolecular Coulombic decay | 2022 | Nature Communications 13, 5335 |
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| Abstract: {Intermolecular interactions involving aromatic rings are ubiquitous in biochemistry and they govern the properties of many organic materials. Nevertheless, our understanding of the structures and dynamics of aromatic clusters remains incomplete, in particular for systems beyond the dimers, despite their high presence in many macromolecular systems such as DNA and proteins. Here, we study the fragmentation dynamics of benzene trimer that represents a prototype of higher-order aromatic clusters. The trimers are initially ionized by electron-collision with the creation of a deep-lying carbon 2s-1 state or one outer-valence and one inner-valence vacancies at two separate molecules. The system can thus relax via ultrafast intermolecular decay mechanisms, leading to the formation of C6H6+-C6H6+-C6H6+ trications and followed by a concerted three-body Coulomb explosion. Triple-coincidence ion momentum spectroscopy, accompanied by ab-initio calculations and further supported by strong-field laser experiments, allows us to elucidate the details on the fragmentation dynamics of benzene trimers.} | ||||||
BibTeX:
@article{Zhou22_2,
author = {Zhou, J. and Yu, X. and Luo, S. and Xue, X. and Jia, S. and Zhang, X. and Zhao, Y. and Hao, X. and He, L. and Wang, C. and Ding, D. and Ren, X.},
title = {{Triple ionization and fragmentation of benzene trimers following ultrafast intermolecular Coulombic decay}},
journal = {Nature Communications},
year = {2022},
volume = {13},
pages = {5335},
note = {experiment},
doi = {https://doi.org/10.1038/s41467-022-33032-2}
}
|
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| P. Zhang, C. Perry, T.T. Luu, D. Matselyukh & H.J. Wörner | Intermolecular Coulombic Decay in Liquid Water | 2022 | Phys. Rev. Lett. 128, 133001 |
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| Abstract: {We report the first observation of intermolecular Coulombic decay (ICD) in liquid water following inner-valence ionization. By combining a monochromatized tabletop high-harmonic source with a liquid microjet, we record electron-electron coincidence spectra at two photon energies that identify the ICD electrons, together with the photoelectrons originating from the 2a1 inner-valence band of liquid water. Our results confirm the importance of ICD as a source of low-energy electrons in bulk liquid water and provide quantitative results for modeling the velocity distribution of the slow electrons that are thought to dominate radiation damage in aqueous environments.} | ||||||
BibTeX:
@article{Zheng22,
author = {Zhang, P. and Perry, C. and Luu, T. T. and Matselyukh, D. and Wörner, H. J.},
title = {{Intermolecular Coulombic Decay in Liquid Water}},
journal = {Phys. Rev. Lett.},
publisher = {American Physical Society},
year = {2022},
volume = {128},
issue = {13},
pages = {133001},
numpages = {6},
note = {experiment},
doi = {https://doi.org/10.1103/PhysRevLett.128.133001}
}
|
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| D. Uhl, A. Wituschek, R. Michiels, F. Trinter, T. Jahnke, E. Allaria, C. Callegari, M. Danailov, M. Di Fraia, O. Plekan, U. Bangert, K. Dulitz, F. Landmesser, M. Michelbach, A. Simoncig, M. Manfredda, S. Spampinati, G. Penco, R.J. Squibb, R. Feifel, T. Laarmann, M. Mudrich, K.C. Prince, G. Cerullo, L. Giannessi, F. Stienkemeier & L. Bruder | Extreme Ultraviolet Wave Packet Interferometry of the Autoionizing HeNe Dimer | 2022 | J. Phys. Chem. Lett. 13, 8470-8476 |
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| Abstract: {Femtosecond extreme ultraviolet wave packet interferometry (XUV-WPI) was applied to study resonant interatomic Coulombic decay (ICD) in the HeNe dimer. The high demands on phase stability and sensitivity for vibronic XUV-WPI of molecular-beam targets are met using an XUV phase-cycling scheme. The detected quantum interferences exhibit vibronic dephasing and rephasing signatures along with an ultrafast decoherence assigned to the ICD process. A Fourier analysis reveals the molecular absorption spectrum with high resolution. The demonstrated experiment shows a promising route for the real-time analysis of ultrafast ICD processes with both high temporal and high spectral resolution.} | ||||||
BibTeX:
@article{Uhl22,
author = {Uhl, D. and Wituschek, A. and Michiels, R. and Trinter, F. and Jahnke, T. and Allaria, E. and Callegari, C. and Danailov, M. and Di Fraia, M. and Plekan, O. and Bangert, U. and Dulitz, K. and Landmesser, F. and Michelbach, M. and Simoncig, A. and Manfredda, M. and Spampinati, S. and Penco, G. and Squibb, R. J. and Feifel, R. and Laarmann, T. and Mudrich, M. and Prince, K. C. and Cerullo, G. and Giannessi, L. and Stienkemeier, F. and Bruder, L.},
title = {{Extreme Ultraviolet Wave Packet Interferometry of the Autoionizing HeNe Dimer}},
journal = {J. Phys. Chem. Lett.},
year = {2022},
volume = {13},
pages = {8470-8476},
note = {experiment},
doi = {https://doi.org/10.1021/acs.jpclett.2c01619}
}
|
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| E. Pelimanni, A. Hans, E. Heikura, M. Huttula & M. Patanen | Efficient neutralization of core ionized species in an aqueous environment | 2022 | Phys. Chem. Chem. Phys. 24, 11646-11653 |
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| Abstract: {Core ionization dynamics of argon–water heteroclusters ArM[H2O]N are investigated using a site and process selective experimental scheme combining 3 keV electron irradiation with Auger electron-ion-ion multi-coincidence detection. The formation of Ar 2p-1 vacancies followed by non-radiative decay to intermediate one-site doubly ionized states Ar2+(3p-2)–ArM-1[H2O]N and subsequent redistribution of charge to the cluster environment are monitored. At low argon concentrations the emission of an [H2O]n'H+/[H2O]n''H+ ion pair is the dominant outcome, implying on high efficiency of charge transfer to the water network. Increasing the condensation fraction of argon in the mixed clusters and/or to pure argon clusters is reflected as a growing yield of Arm'+/Arm''+ ion pairs, providing a fingerprint of the precursor heterocluster beam composition. The coincident Auger electron spectra, resolved with better than 1 eV resolution, show only subtle differences and thereby reflect the local nature of the initial Auger decay step. The results lead to better understanding of inner shell ionization processes in heterogeneous clusters and in aqueous environments in general.} | ||||||
BibTeX:
@article{Pelimanni22,
author = {Pelimanni, E. and Hans, A. and Heikura, E. and Huttula, M. and Patanen, M.},
title = {{Efficient neutralization of core ionized species in an aqueous environment}},
journal = {Phys. Chem. Chem. Phys.},
publisher = {The Royal Society of Chemistry},
year = {2022},
volume = {24},
pages = {11646-11653},
note = {experiment},
doi = {https://doi.org/10.1039/D2CP01178F}
}
|
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| A.C. LaForge, J.D. Asmussen, B. Bastian, M. Bonanomi, C. Callegari, S. De, M. Di Fraia, L. Gorman, S. Hartweg, S.R. Krishnan, M.F. Kling, D. Mishra, S. Mandal, A. Ngai, N. Pal, O. Plekan, K.C. Prince, P. Rosenberger, E. Aguirre Serrata, F. Stienkemeier, N. Berrah & M. Mudrich | Relaxation dynamics in excited helium nanodroplets probed with high resolution, time-resolved photoelectron spectroscopy | 2022 | Phys. Chem. Chem. Phys. 24, 28844-28852 |
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| Abstract: {Superfluid helium nanodroplets are often considered as transparent and chemically inert nanometer-sized cryo-matrices for high-resolution or time-resolved spectroscopy of embedded molecules and clusters. On the other hand, when the helium nanodroplets are resonantly excited with XUV radiation, a multitude of ultrafast processes are initiated, such as relaxation into metastable states, formation of nanoscopic bubbles or excimers, and autoionization channels generating low-energy free electrons. Here, we discuss the full spectrum of ultrafast relaxation processes observed when helium nanodroplets are electronically excited. In particular, we perform an in-depth study of the relaxation dynamics occurring in the lowest 1s2s and 1s2p droplet bands using high resolution, time-resolved photoelectron spectroscopy. The simplified excitation scheme and improved resolution allow us to identify the relaxation into metastable triplet and excimer states even when exciting below the droplets' autoionization threshold, unobserved in previous studies.} | ||||||
BibTeX:
@article{LaForge22,
author = {LaForge, A. C. and Asmussen, J. D. and Bastian, B. and Bonanomi, M. and Callegari, C. and De, S. and Di Fraia, M. and Gorman, L. and Hartweg, S. and Krishnan, S. R. and Kling, M. F. and Mishra, D. and Mandal, S. and Ngai, A. and Pal, N. and Plekan, O. and Prince, K. C. and Rosenberger, P. and Aguirre Serrata, E. and Stienkemeier, F. and Berrah, N. and Mudrich, M.},
title = {{Relaxation dynamics in excited helium nanodroplets probed with high resolution, time-resolved photoelectron spectroscopy}},
journal = {Phys. Chem. Chem. Phys.},
publisher = {The Royal Society of Chemistry},
year = {2022},
volume = {24},
issue = {47},
pages = {28844-28852},
note = {experiment},
doi = {https://doi.org/10.1039/D2CP03335F}
}
|
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| L. Bruder, M. Koch, M. Mudrich & F. Stienkemeier | Ultrafast Dynamics in Helium Droplets | 2022 | ,Molecules in Superfluid Helium Nanodroplets: Spectroscopy, Structure, and Dynamics 447-511 |
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| Abstract: {Helium nanodroplets are peculiar systems, as condensed superfluid entities on the nanoscale, and as vessels for studies of molecules and molecular aggregates and their quantum properties at very low temperature. For both aspects, the dynamics upon the interaction with light is fundamental for understanding the properties of the systems. In this chapter we focus on time-resolved experiments in order to study ultrafast dynamics in neat as well as doped helium nanodroplets. Recent experimental approaches are reviewed, ranging from time-correlated photon detection to femtosecond pump-probe photoelectron and photoion spectroscopy, coherent multidimensional spectroscopy as well as applications of strong laser fields and novel, extreme ultraviolet light sources. The experiments examined in more detail investigate the dynamics of atomic and molecular dopants, including coherent wave packet dynamics and long-lived vibrational coherences of molecules attached to and immersed inside helium droplets. Furthermore, the dynamics of highly-excited helium droplets including interatomic Coulombic decay and nanoplasma states are discussed. Finally, an outlook concludes on the perspectives of time-resolved experiments with helium droplets, including recent options provided by new radiation sources of femto- or even attosecond laser pulses up to the soft X-ray range.} | ||||||
BibTeX:
@inbook{Bruder22,
author = {Bruder, L. and Koch, M. and Mudrich, M. and Stienkemeier, F.},
title = {{Ultrafast Dynamics in Helium Droplets}},
booktitle = {Molecules in Superfluid Helium Nanodroplets: Spectroscopy, Structure, and Dynamics},
publisher = {Springer International Publishing},
year = {2022},
pages = {447--511},
note = {experiment},
doi = {https://doi.org/10.1007/978-3-030-94896-2_10}
}
|
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| S. Yan, R.T. Zhang, S. Xu, S.F. Zhang & X. Ma | Molecular Ionization Dissociation Induced by Interatomic Coulombic Decay in an ArCH_4-Electron Collision System | 2023 | Phys. Rev. Lett. 131, 253001 |
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| Abstract: {Interatomic Coulombic decay (ICD) is a significant fragmentation mechanism observed in weakly bound systems. It has been widely accepted that ICD-induced molecular fragmentation occurs through a two-step process, involving ICD as the first step and dissociative-electron attachment (DEA) as the second step. In this study, we conducted a fragmentation experiment of ArCH4 by electron impact, utilizing the coincident detection of one electron and two ions. In addition to the well-known decay pathway that induces pure ionization of CH4, we observed a new channel where ICD triggers the ionization dissociation of CH4, resulting in the cleavage of the C-H bond and the formation of the CH3+ and H ion pair. The high efficiency of this channel, as indicated by the relative yield of the Ar+/CH3+ ion pair, agrees with the theoretical prediction [L. S. Cederbaum, J. Phys. Chem. Lett. 11, 8964 (2020).; Y. C. Chiang et al., Phys. Rev. A 100, 052701 (2019).]. These results suggest that ICD can directly break covalent bonds with high efficiency, bypassing the need for DEA. This finding introduces a novel approach to enhance the fragmentation efficiency of molecules containing covalent bonds, such as DNA backbone.} | ||||||
BibTeX:
@article{Yan23,
author = {Yan, S. and Zhang, R. T. and Xu, S. and Zhang, S. F. and Ma, X.},
title = {{Molecular Ionization Dissociation Induced by Interatomic Coulombic Decay in an ${\mathrm{ArCH}}_{4}$-Electron Collision System}},
journal = {Phys. Rev. Lett.},
publisher = {American Physical Society},
year = {2023},
volume = {131},
issue = {25},
pages = {253001},
numpages = {6},
note = {experiment},
doi = {https://doi.org/10.1103/PhysRevLett.131.253001}
}
|
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| M.A.K.A. Siddiki, L.C. Tribedi & D. Misra | Probing the Fragmentation Pathways of an Argon Dimer in Slow Ion–Dimer Collisions | 2023 | Atoms 11, 34 |
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| Abstract: {We report the development of a supersonic jet assembly to study electron transfer collisions with atoms, molecules, and van der Waals clusters. A comparative study of Ar monomer and dimer cations is presented for different capture-associated channels with a 2.5 keV/u O2+ projectile beam. For the Ar+ + Ar+ fragmentation channel, the interatomic relaxation channels are discussed. The vacancies of the dimer single site or double site show the dependence on capture mechanisms. In the Ar2+ + Ar+ fragmentation channel, double capture, in addition to the single ionization process, dominates. The orientation effect reflects the maximum yield at around 50 and 130 degrees, and angular distributions are nearly symmetric about the axis perpendicular to the dimer axis.} | ||||||
BibTeX:
@article{Saddiki23,
author = {Siddiki, M. A. K. A. and Tribedi, L. C. and Misra, D.},
title = {{Probing the Fragmentation Pathways of an Argon Dimer in Slow Ion–Dimer Collisions}},
journal = {Atoms},
year = {2023},
volume = {11},
pages = {34},
note = {experiment},
doi = {https://doi.org/10.3390/atoms11020034}
}
|
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| C. Lu, M. Shi, S. Pan, L. Zhou, J. Qiang, P. Lu, W. Zhang & J. Wu | Electron transfer in strong-field three-body fragmentation of ArKr2 trimers | 2023 | J. Chem. Phys. 158, 094302 |
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| Abstract: {We experimentally studied the three-body fragmentation dynamics of a noble gas cluster (ArKr2) upon its multiple ionization by an intense femtosecond laser pulse. The three-dimensional momentum vectors of correlated fragmental ions were measured in coincidence for each fragmentation event. A novel comet-like structure was observed in the Newton diagram of the quadruple-ionization-induced breakup channel of ArKr24+ → Ar+ + Kr+ + Kr2+. The concentrated head part of the structure mainly originates from the direct Coulomb explosion process, while the broader tail part of the structure stems from a three-body fragmentation process involving electron transfer between the distant Kr+ and Kr2+ ion fragments. Due to the field-driven electron transfer, the Coulomb repulsive force of the Kr2+ and Kr+ ions with respect to the Ar+ ion undergoes exchange, leading to changes in the ion emission geometry in the Newton plot. An energy sharing among the separating Kr2+ and Kr+ entities was observed. Our study indicates a promising approach for investigating the strong-field-driven intersystem electron transfer dynamics by using the Coulomb explosion imaging of an isosceles triangle van der Waals cluster system.} | ||||||
BibTeX:
@article{Lu23,
author = {Lu,C. and Shi,M. and Pan,S. and Zhou,L. and Qiang,J. and Lu,P. and Zhang,W. and Wu,J. },
title = {{Electron transfer in strong-field three-body fragmentation of ArKr2 trimers}},
journal = {J. Chem. Phys.},
year = {2023},
volume = {158},
pages = {094302},
note = {experiment},
doi = {https://doi.org/10.1063/5.0134833}
}
|
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| E. Evlyukhin, P. Cifligu, M. Pravica, P.K. Bhowmik, E. Kim, D. Popov & C. Park | Experimental demonstration of necessary conditions for X-ray induced synthesis of cesium superoxide | 2023 | Phys. Chem. Chem. Phys. 25, 1799-1807 |
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| Abstract: {Absorption of sufficiently energetic X-ray photons by a molecular system results in a cascade of ultrafast electronic relaxation processes which leads to a distortion and dissociation of its molecular structure. Here, we demonstrate that only decomposition of powdered cesium oxalate monohydrate induced by monochromatic X-ray irradiation under high pressure leads to the formation of cesium superoxide. Whereas, for an unhydrated form of cesium oxalate subjected to the same extreme conditions, only degradation of the electron density distribution is observed. Moreover, the corresponding model of X-ray induced electronic relaxation cascades with an emphasis on water molecules' critical role is proposed. Our experimental results suggest that the presence of water molecules in initially solid-state systems (i.e. additional electronic relaxation channels) together with applied high pressure (reduced interatomic/intermolecular distance) could potentially be a universal criteria for chemical and structural synthesis of novel compounds via X-ray induced photochemistry.} | ||||||
BibTeX:
@article{Evlyukhin23,
author = {Evlyukhin, E. and Cifligu, P. and Pravica, M. and Bhowmik, P. K. and Kim, E. and Popov, D. and Park, C.},
title = {{Experimental demonstration of necessary conditions for X-ray induced synthesis of cesium superoxide}},
journal = {Phys. Chem. Chem. Phys.},
publisher = {The Royal Society of Chemistry},
year = {2023},
volume = {25},
issue = {3},
pages = {1799-1807},
note = {experiment},
doi = {https://doi.org/10.1039/D2CP04767E}
}
|
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| L. Jurkovičová, L. Ben Ltaief, A. Hult Roos, O. Hort, O. Finke, M. Albrecht, Z. Hoque, E. Klimešová, A. Sundaralingam, R. Antipenkov, A. Grenfell, A. Špaček, W. Szuba, M. Krikunova, M. Mudrich, J. Nejdl & J. Andreasson | Bright continuously tunable vacuum ultraviolet source for ultrafast spectroscopy | 2024 | Commun. Phys. 7, 26 |
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| Abstract: {Ultrafast electron dynamics drive phenomena such as photochemical reactions, catalysis, and light harvesting. To capture such dynamics in real-time, femtosecond to attosecond light sources are extensively used. However, an exact match between the excitation photon energy and a characteristic resonance is crucial. High-harmonic generation sources are advantageous in terms of pulse duration but limited in spectral tunability in the vacuum ultraviolet range. Here, we present a monochromatic femtosecond source continuously tunable around 21 eV photon energy utilizing the second harmonic of an optical parametric chirped pulse amplification laser system to drive high-harmonic generation. The unique tunability of the source is verified in an experiment probing the interatomic Coulombic decay in doped He nanodroplets across the He absorption bands. Moreover, we achieved intensities sufficient for driving collective processes in multiply excited helium nanodroplets, which have been previously observed only at free electron lasers.} | ||||||
BibTeX:
@article{Jurkovicova24,
author = {Jurkovičová, L. and Ben Ltaief, L. and Hult Roos, A. and Hort, O. and Finke, O. and Albrecht, M. and Hoque, Z. and Klimešová, E. and Sundaralingam, A. and Antipenkov, R. and Grenfell, A. and Špaček, A. and Szuba, W. and Krikunova, M. and Mudrich, M. and Nejdl, J. and Andreasson, J.},
title = {{Bright continuously tunable vacuum ultraviolet source for ultrafast spectroscopy}},
journal = {Commun. Phys.},
year = {2024},
volume = {7},
pages = {26},
note = {experiment},
doi = {https://doi.org/10.1038/s42005-023-01513-5}
}
|
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| Y. Hikosaka | Dissociation following the Auger decay of xenon difluoride molecules | 2024 | J. Chem. Phys. 160, 024304 |
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| Abstract: {{This study investigated the dissociation after the Xe 4d Auger decay of weak-bonding XeF2 molecules by multielectron–ion coincidence spectroscopy using a magnetic bottle electron spectrometer. Fragmentations from the XeF22+ states were clarified in the Auger spectra coincident with individual ion species. It was observed that the two-hole population led by the Auger decay was not directly inherited during the fragmentation of XeF22+. Furthermore, the dissociations of XeF23+ states produced by the double Auger decay were investigated.}} | ||||||
BibTeX:
@article{Hikosaka24,
author = {Hikosaka, Y.},
title = {{{Dissociation following the Auger decay of xenon difluoride molecules}}},
journal = {J. Chem. Phys.},
year = {2024},
volume = {160},
pages = {024304},
note = {experiment},
doi = {https://doi.org/10.1063/5.0186619}
}
|
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| R. Dupuy, T. Buttersack, F. Trinter, C. Richter, S. Gholami, O. Björneholm, U. Hergenhahn, B. Winter & H. Bluhm | The solvation shell probed by resonant intermolecular Coulombic decay | 2024 | Nat. Commun. 15, 6926 |
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| Abstract: {Molecules involved in solvation shells have properties differing from those of the bulk solvent, which can in turn affect reactivity. Among key properties of these molecules are their nature and electronic structure. Widely used tools to characterize this type of property are X-ray-based spectroscopies, which, however, usually lack the capability to selectively probe the solvation-shell molecules. A class of X-ray triggered ``non-local'' processes has the recognized potential to provide this selectivity. Intermolecular Coulombic decay (ICD) and related processes involve neighbouring molecules in the decay of the X-ray-excited target, and are thus naturally sensitive to its immediate environment. Applying electron spectroscopy to aqueous solutions, we explore the resonant flavours of ICD and demonstrate how it can inform on the first solvation shell of excited solvated cations. One particular ICD process turns out to be a potent marker of the formation of ion pairs. Another gives a direct access to the electron binding energies of the water molecules in the first solvation shell, a quantity previously elusive to direct measurements. The resonant nature of the processes makes them readily measurable, providing powerful new spectroscopic tools.} | ||||||
BibTeX:
@article{Dupuy24,
author = {Dupuy, R. and Buttersack, T. and Trinter, F. and Richter, C. and Gholami, S. and Björneholm, O. and Hergenhahn, U. and Winter, B. and Bluhm, H.},
title = {{The solvation shell probed by resonant intermolecular Coulombic decay}},
journal = {Nat. Commun.},
year = {2024},
volume = {15},
pages = {6926},
note = {experiment},
doi = {https://doi.org/10.1038/s41467-024-51417-3}
}
|
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| D. Bloß, F. Trinter, I. Unger, Ch. Zindel, C. Honisch, J. Viehmann, N. Kiefer, L. Marder, C. Küstner-Wetekam, E. Heikura, L.S. Cederbaum, O. Björneholm, U. Hergenhahn, A. Ehresmann & A. Hans | X-ray radiation damage cycle of solvated inorganic ions | 2024 | Nature Commun. 15, 4594 |
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| Abstract: {X-ray-induced damage is one of the key topics in radiation chemistry. Substantial damage is attributed to low-energy electrons and radicals emerging from direct inner-shell photoionization or produced by subsequent processes. We apply multi-electron coincidence spectroscopy to X-ray-irradiated aqueous solutions of inorganic ions to investigate the production of low-energy electrons (LEEs) in a predicted cascade of intermolecular charge- and energy-transfer processes, namely electron-transfer-mediated decay (ETMD) and interatomic/intermolecular Coulombic decay (ICD). An advanced coincidence technique allows us to identify several LEE-producing steps during the decay of 1s vacancies in solvated Mg2+ ions, which escaped observation in previous non-coincident experiments. We provide strong evidence for the predicted recovering of the ion's initial state. In natural environments the recovering of the ion's initial state is expected to cause inorganic ions to be radiation-damage hot spots, repeatedly producing destructive particles under continuous irradiation.} | ||||||
BibTeX:
@article{Bloss24,
author = {Bloß, D. and Trinter, F. and Unger, I. and Zindel, Ch. and Honisch, C. and Viehmann, J. and Kiefer, N. and Marder, L. and Küstner-Wetekam, C. and Heikura, E. and Cederbaum, L. S. and Björneholm, O. and Hergenhahn, U. and Ehresmann, A. and Hans, A.},
title = {{X-ray radiation damage cycle of solvated inorganic ions}},
journal = {Nature Commun.},
year = {2024},
volume = {15},
pages = {4594},
note = {experiment},
doi = {https://doi.org/10.1038/s41467-024-48687-2}
}
|
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| L. Ben Ltaief, K. Sishodia, R. Richter, B. Bastian, J.D. Asmussen, S. Mandal, N. Pal, C. Medina, S.R. Krishnan, K. von Haeften & M. Mudrich | Spectroscopically resolved resonant interatomic Coulombic decay in photoexcited large He nanodroplets | 2024 | Phys. Rev. Res. 6, 013019 |
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| Abstract: {Interatomic Coulombic decay (ICD) processes play a crucial role in weakly bound complexes exposed to intense or high-energy radiation. Using large helium nanodroplets, we demonstrate that ICD is efficient even when the droplets are irradiated by weak synchrotron radiation at relatively low photon energies. Below the ionization threshold, resonant excitation of multiple centers efficiently induces resonant ICD as previously observed for intense pulses [A. C. LaForge et al., Phys. Rev. X 11, 021011 (2021)]. More surprisingly, we observe ICD even above the ionization threshold due to recombination of photoelectrons and ions into excited states which subsequently decay by ICD. This demonstrates the importance of secondary processes, in particular electron scattering and recombination, in inducing ICD in extended condensed phase systems. High-resolution ICD electron spectra in combination with coincidence imaging of electrons and ions reveal the relaxation dynamics of highly excited and ionized weakly bound nanosystems.} | ||||||
BibTeX:
@article{Ltaief24,
author = {Ben Ltaief, L. and Sishodia, K. and Richter, R. and Bastian, B. and Asmussen, J. D. and Mandal, S. and Pal, N. and Medina, C. and Krishnan, S. R. and von Haeften, K. and Mudrich, M.},
title = {{Spectroscopically resolved resonant interatomic Coulombic decay in photoexcited large He nanodroplets}},
journal = {Phys. Rev. Res.},
publisher = {American Physical Society},
year = {2024},
volume = {6},
issue = {1},
pages = {013019},
numpages = {15},
note = {experiment},
doi = {https://doi.org/10.1103/PhysRevResearch.6.013019}
}
|
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