Two-dimensional (2D) electron momentum distributions and energy spectra for multiphoton ionization of atoms by intense laser pulses, calculated by solving the time-dependent Schrödinger equation (TDSE) for different wavelengths and intensities, are compared to those predicted by the strong-field approximation (SFA). It is shown that the momentum spectra at low energies between the TDSE and SFA are quite different and the differences arise largely from the absence of a long-range Coulomb interaction in the SFA. We further found that the low-energy 2D momentum spectra from the TDSE exhibit ubiquitous fanlike features where the number of stripes is due to a single dominant angular momentum of the low-energy electron. The specific dominant angular momentum in turn has been found to be decided by the minimum number of photons needed to ionize the atom only. The electron momentum spectra predicted by models modified from the SFA are also examined and found to lack the fanlike features as in the SFA.
Z. Chen et al., "Analysis of Two-Dimensional Photoelectron Momentum Spectra and the Effect of the Long-Range Coulomb Potential in Single Ionization of Atoms by Intense Lasers," Physical Review A - Atomic, Molecular, and Optical Physics, vol. 74, no. 5, American Physical Society (APS), Nov 2006.
The definitive version is available at https://doi.org/10.1103/PhysRevA.74.053405
Keywords and Phrases
Feature Extraction; Ionization; Photoelectron Spectroscopy; Photons; Spectrum Analysis; Wave Equations, Coulomb Potential; Electron Momentum; Energy Spectra; Photoelectron Momentum Spectra; Single Ionization, Lasers
International Standard Serial Number (ISSN)
Article - Journal
© 2006 American Physical Society (APS), All rights reserved.