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Title: Time-dependent density-functional theory of strong-field ionization of atoms by soft x rays

Authors:
; ; ; ; ; ; ; ; ; ;
Publication Date:
Sponsoring Org.:
USDOE Office of Nuclear Energy (NE), Fuel Cycle Technologies (NE-5)
OSTI Identifier:
1179653
Grant/Contract Number:
SFRH/BPD/44608/2008
Resource Type:
Journal Article: Publisher's Accepted Manuscript
Journal Name:
Physical Review A
Additional Journal Information:
Journal Volume: 90; Journal Issue: 3; Related Information: CHORUS Timestamp: 2017-06-22 16:17:29; Journal ID: ISSN 1050-2947
Publisher:
American Physical Society
Country of Publication:
United States
Language:
English

Citation Formats

Crawford-Uranga, A., De Giovannini, U., Räsänen, E., Oliveira, M. J. T., Mowbray, D. J., Nikolopoulos, G. M., Karamatskos, E. T., Markellos, D., Lambropoulos, P., Kurth, S., and Rubio, A.. Time-dependent density-functional theory of strong-field ionization of atoms by soft x rays. United States: N. p., 2014. Web. doi:10.1103/PhysRevA.90.033412.
Crawford-Uranga, A., De Giovannini, U., Räsänen, E., Oliveira, M. J. T., Mowbray, D. J., Nikolopoulos, G. M., Karamatskos, E. T., Markellos, D., Lambropoulos, P., Kurth, S., & Rubio, A.. Time-dependent density-functional theory of strong-field ionization of atoms by soft x rays. United States. doi:10.1103/PhysRevA.90.033412.
Crawford-Uranga, A., De Giovannini, U., Räsänen, E., Oliveira, M. J. T., Mowbray, D. J., Nikolopoulos, G. M., Karamatskos, E. T., Markellos, D., Lambropoulos, P., Kurth, S., and Rubio, A.. Thu . "Time-dependent density-functional theory of strong-field ionization of atoms by soft x rays". United States. doi:10.1103/PhysRevA.90.033412.
@article{osti_1179653,
title = {Time-dependent density-functional theory of strong-field ionization of atoms by soft x rays},
author = {Crawford-Uranga, A. and De Giovannini, U. and Räsänen, E. and Oliveira, M. J. T. and Mowbray, D. J. and Nikolopoulos, G. M. and Karamatskos, E. T. and Markellos, D. and Lambropoulos, P. and Kurth, S. and Rubio, A.},
abstractNote = {},
doi = {10.1103/PhysRevA.90.033412},
journal = {Physical Review A},
number = 3,
volume = 90,
place = {United States},
year = {Thu Sep 11 00:00:00 EDT 2014},
month = {Thu Sep 11 00:00:00 EDT 2014}
}

Journal Article:
Free Publicly Available Full Text
Publisher's Version of Record at 10.1103/PhysRevA.90.033412

Citation Metrics:
Cited by: 15works
Citation information provided by
Web of Science

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  • Cited by 4
  • We report a numerical study of strong-field ionization rates of the H{sub 2} molecule using time-dependent density-functional theory (TDDFT). In the dc field limit, TDDFT results for the rate of tunneling ionization agree with molecular Ammosov-Delone-Kralnov (MO-ADK) predictions, as well as results from a complex scaling method at the full configuration interaction level. Our study demonstrates the effect of photon energy, molecular vibration, and orientation on the ionization. Calculated rates for 800-nm lasers are about four times greater than the values predicted by the slowly varying field approximation for tunneling ionization. The rate for the ground vibrational state is highermore » than that of the fixed nuclei value at the equilibrium distance. This difference decreases with increasing field intensity. When the field intensity is sufficiently high, the two rates are very similar, and the fixed nuclear distance rate may be used to approximate the ground-vibrational-state rate. TDDFT methods predict an anisotropy slightly larger than the prediction obtained from the MO-ADK method. We also find that the field intensity plays a role in the anisotropy, which the MO-ADK results do not show.« less
  • We compare strong-field ionization probabilities of N{sub 2} and F{sub 2} molecules using time-dependent density functional theory calculations. Accurate nuclear potentials and ground vibrational wave functions are incorporated into our study. For both molecules, the effect of molecular vibration is small, while that of the molecular orientation is significant. When compared to the ionization probability of a molecule at the equilibrium geometry, we estimate the effect of the ground state vibration to be within 3% for N{sub 2} and within 6% for F{sub 2} in the intensity range from 1 to 5x10{sup 14} W/cm{sup 2}. The molecular-orientation-dependent ionization probabilities formore » both molecules at various intensities are presented. They are strongly dependent on the laser intensity, and the anisotropy diminishes when the laser intensity is high. For laser intensities of 1.6 and 2.2x10{sup 14} W/cm{sup 2} we find ionization probability ratios of 5.9 and 4.3, respectively, for the parallel versus perpendicular orientation of N{sub 2}. This is reasonably consistent with experimental measurements. For randomly oriented molecules, the ratio of the probabilities for N{sub 2} and F{sub 2} increases from about 1 at 10{sup 14} W/cm{sup 2} to 2 at 4x10{sup 14} W/cm{sup 2}, which agrees well with experimental results.« less
  • We investigate the possibility to deduce momentum space properties from time-dependent density functional calculations. Electron and ion momentum distributions after double ionization of a model helium atom in a strong few-cycle laser pulse are studied. We show that, in this case, the choice of suitable functionals for the observables is considerably more important than the choice of the correlation potential in the time-dependent Kohn-Sham equations. By comparison with the solution of the time-dependent Schroedinger equation, the insufficiency of functionals neglecting electron correlation is demonstrated. We construct a functional of the Kohn-Sham orbitals, which in principle yields the exact momentum distributionsmore » of the electrons and the ion. The product-phase approximation is introduced, which reduces the problem of approximating this functional significantly.« less
  • We present a time-dependent density-functional theory approach with proper long-range potential for an ab initio study of the effect of correlated multielectron responses on the multiphoton ionization (MPI) and high-order harmonic generation (HHG) of diatomic molecules N{sub 2} and F{sub 2} in intense short laser pulse fields with arbitrary molecular orientation. We show that the contributions of inner molecular orbitals to the total MPI probability can be sufficiently large or even dominant over the highest-occupied molecular orbital, depending on detailed electronic structure and symmetry, laser field intensity, and orientation angle. The multielectron effects in HHG are also very important. Theymore » are responsible for enhanced HHG at some orientations of the molecular axis. Even strongly bound electrons may have a significant influence on the HHG process.« less