Precision calculation of abovethreshold multiphoton ionization in intense shortwavelength laser fields: The momentumspace approach and timedependent generalized pseudospectral method
Abstract
We present an approach in momentum (P) space for the accurate study of multiphoton and abovethreshold ionization (ATI) dynamics of atomic systems driven by intense laser fields. In this approach, the electron wave function is calculated by solving the Pspace timedependent Schroedinger equation (TDSE) in a finite Pspace volume under a simple zero asymptotic boundary condition. The Pspace TDSE is propagated accurately and efficiently by means of the timedependent generalized pseudospectral method with optimal momentum grid discretization and a splitoperator time propagator in the energy representation. The differential ionization probabilities are calculated directly from the continuumstate wave function obtained by projecting the total electron wave function onto the continuumstate 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 shortwavelength laser fields. Highresolution photoelectron energyangular distribution and ATI spectra have been obtained. We find that with the increase of the laser intensity, the photoelectron energyangular 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 »
 Authors:

 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 10502947
 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; MULTIPHOTON PROCESSES; PHOTOIONIZATION; PROBABILITY; PROJECTION OPERATORS; SCHROEDINGER EQUATION; SPACETIME; 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, ShihI, and Center for Quantum Science and Engineering, Department of Physics, National Taiwan University, Taipei 10617, Taiwan. Precision calculation of abovethreshold multiphoton ionization in intense shortwavelength laser fields: The momentumspace approach and timedependent generalized pseudospectral method. United States: N. p., 2011.
Web. doi:10.1103/PHYSREVA.83.013405.
Zhongyuan, Zhou, Chu, ShihI, & Center for Quantum Science and Engineering, Department of Physics, National Taiwan University, Taipei 10617, Taiwan. Precision calculation of abovethreshold multiphoton ionization in intense shortwavelength laser fields: The momentumspace approach and timedependent generalized pseudospectral method. United States. https://doi.org/10.1103/PHYSREVA.83.013405
Zhongyuan, Zhou, Chu, ShihI, and Center for Quantum Science and Engineering, Department of Physics, National Taiwan University, Taipei 10617, Taiwan. Sat .
"Precision calculation of abovethreshold multiphoton ionization in intense shortwavelength laser fields: The momentumspace approach and timedependent generalized pseudospectral method". United States. https://doi.org/10.1103/PHYSREVA.83.013405.
@article{osti_21529095,
title = {Precision calculation of abovethreshold multiphoton ionization in intense shortwavelength laser fields: The momentumspace approach and timedependent generalized pseudospectral method},
author = {Zhongyuan, Zhou and Chu, ShihI 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 abovethreshold ionization (ATI) dynamics of atomic systems driven by intense laser fields. In this approach, the electron wave function is calculated by solving the Pspace timedependent Schroedinger equation (TDSE) in a finite Pspace volume under a simple zero asymptotic boundary condition. The Pspace TDSE is propagated accurately and efficiently by means of the timedependent generalized pseudospectral method with optimal momentum grid discretization and a splitoperator time propagator in the energy representation. The differential ionization probabilities are calculated directly from the continuumstate wave function obtained by projecting the total electron wave function onto the continuumstate 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 shortwavelength laser fields. Highresolution photoelectron energyangular distribution and ATI spectra have been obtained. We find that with the increase of the laser intensity, the photoelectron energyangular 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 strongfield atomic stabilization phenomenon in detail.},
doi = {10.1103/PHYSREVA.83.013405},
url = {https://www.osti.gov/biblio/21529095},
journal = {Physical Review. A},
issn = {10502947},
number = 1,
volume = 83,
place = {United States},
year = {2011},
month = {1}
}