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Title: Precision calculation of above-threshold multiphoton ionization in intense short-wavelength laser fields: The momentum-space approach and time-dependent generalized pseudospectral method

Abstract

We present an approach in momentum (P) space for the accurate study of multiphoton and above-threshold ionization (ATI) dynamics of atomic systems driven by intense laser fields. In this approach, the electron wave function is calculated by solving the P-space time-dependent Schroedinger equation (TDSE) in a finite P-space volume under a simple zero asymptotic boundary condition. The P-space TDSE is propagated accurately and efficiently by means of the time-dependent generalized pseudospectral method with optimal momentum grid discretization and a split-operator time propagator in the energy representation. The differential ionization probabilities are calculated directly from the continuum-state wave function obtained by projecting the total electron wave function onto the continuum-state subspace using the projection operator constructed by the continuum eigenfunctions of the unperturbed Hamiltonian. As a case study, we apply this approach to the nonperturbative study of the multiphoton and ATI dynamics of a hydrogen atom exposed to intense short-wavelength laser fields. High-resolution photoelectron energy-angular distribution and ATI spectra have been obtained. We find that with the increase of the laser intensity, the photoelectron energy-angular distribution changes from circular to dumbbell shaped and is squeezed along the laser field direction. We also explore the change of the maximum photoelectron energy withmore » laser intensity and strong-field atomic stabilization phenomenon in detail.« less

Authors:
 [1];  [1]
  1. Department of Chemistry, University of Kansas, Lawrence, Kansas 66045 (United States)
Publication Date:
OSTI Identifier:
21529095
Resource Type:
Journal Article
Journal Name:
Physical Review. A
Additional Journal Information:
Journal Volume: 83; Journal Issue: 1; Other Information: DOI: 10.1103/PhysRevA.83.013405; (c) 2011 American Institute of Physics; Journal ID: ISSN 1050-2947
Country of Publication:
United States
Language:
English
Subject:
74 ATOMIC AND MOLECULAR PHYSICS; ACCURACY; ANGULAR DISTRIBUTION; ASYMPTOTIC SOLUTIONS; BOUNDARY CONDITIONS; EIGENFUNCTIONS; ELECTRONS; ENERGY SPECTRA; HAMILTONIANS; HYDROGEN; LASER RADIATION; MATHEMATICAL SPACE; MULTI-PHOTON PROCESSES; PHOTOIONIZATION; PROBABILITY; PROJECTION OPERATORS; SCHROEDINGER EQUATION; SPACE-TIME; STABILIZATION; TIME DEPENDENCE; WAVE FUNCTIONS; WAVELENGTHS; DIFFERENTIAL EQUATIONS; DISTRIBUTION; ELECTROMAGNETIC RADIATION; ELEMENTARY PARTICLES; ELEMENTS; EQUATIONS; FERMIONS; FUNCTIONS; IONIZATION; LEPTONS; MATHEMATICAL OPERATORS; MATHEMATICAL SOLUTIONS; NONMETALS; PARTIAL DIFFERENTIAL EQUATIONS; QUANTUM OPERATORS; RADIATIONS; SPACE; SPECTRA; WAVE EQUATIONS

Citation Formats

Zhongyuan, Zhou, Chu, Shih-I, and Center for Quantum Science and Engineering, Department of Physics, National Taiwan University, Taipei 10617, Taiwan. Precision calculation of above-threshold multiphoton ionization in intense short-wavelength laser fields: The momentum-space approach and time-dependent generalized pseudospectral method. United States: N. p., 2011. Web. doi:10.1103/PHYSREVA.83.013405.
Zhongyuan, Zhou, Chu, Shih-I, & Center for Quantum Science and Engineering, Department of Physics, National Taiwan University, Taipei 10617, Taiwan. Precision calculation of above-threshold multiphoton ionization in intense short-wavelength laser fields: The momentum-space approach and time-dependent generalized pseudospectral method. United States. https://doi.org/10.1103/PHYSREVA.83.013405
Zhongyuan, Zhou, Chu, Shih-I, and Center for Quantum Science and Engineering, Department of Physics, National Taiwan University, Taipei 10617, Taiwan. Sat . "Precision calculation of above-threshold multiphoton ionization in intense short-wavelength laser fields: The momentum-space approach and time-dependent generalized pseudospectral method". United States. https://doi.org/10.1103/PHYSREVA.83.013405.
@article{osti_21529095,
title = {Precision calculation of above-threshold multiphoton ionization in intense short-wavelength laser fields: The momentum-space approach and time-dependent generalized pseudospectral method},
author = {Zhongyuan, Zhou and Chu, Shih-I and Center for Quantum Science and Engineering, Department of Physics, National Taiwan University, Taipei 10617, Taiwan},
abstractNote = {We present an approach in momentum (P) space for the accurate study of multiphoton and above-threshold ionization (ATI) dynamics of atomic systems driven by intense laser fields. In this approach, the electron wave function is calculated by solving the P-space time-dependent Schroedinger equation (TDSE) in a finite P-space volume under a simple zero asymptotic boundary condition. The P-space TDSE is propagated accurately and efficiently by means of the time-dependent generalized pseudospectral method with optimal momentum grid discretization and a split-operator time propagator in the energy representation. The differential ionization probabilities are calculated directly from the continuum-state wave function obtained by projecting the total electron wave function onto the continuum-state subspace using the projection operator constructed by the continuum eigenfunctions of the unperturbed Hamiltonian. As a case study, we apply this approach to the nonperturbative study of the multiphoton and ATI dynamics of a hydrogen atom exposed to intense short-wavelength laser fields. High-resolution photoelectron energy-angular distribution and ATI spectra have been obtained. We find that with the increase of the laser intensity, the photoelectron energy-angular distribution changes from circular to dumbbell shaped and is squeezed along the laser field direction. We also explore the change of the maximum photoelectron energy with laser intensity and strong-field atomic stabilization phenomenon in detail.},
doi = {10.1103/PHYSREVA.83.013405},
url = {https://www.osti.gov/biblio/21529095}, journal = {Physical Review. A},
issn = {1050-2947},
number = 1,
volume = 83,
place = {United States},
year = {2011},
month = {1}
}