Two-, three-, and four-photon ionization of Mg in the circularly and linearly polarized laser fields: Comparative study using the Hartree-Fock and model potentials

TL;DR

This study compares two computational methods for calculating multiphoton ionization cross sections of magnesium under different laser polarizations, revealing the effectiveness of model potentials and polarization effects on electron correlations.

Contribution

It introduces a comparative analysis of Hartree-Fock and model potential approaches for multiphoton ionization in Mg, highlighting the accuracy of model potentials and polarization effects.

Findings

Model potential approach yields results comparable or better than Hartree-Fock.

Ionization cross sections vary with photon energy and polarization.

Electron correlations significantly influence ionization ratios.

Abstract

We theoretically study multiphoton ionization of Mg in the circularly as well as the linearly polarized laser fields. Specifically two-, three-, and four-photon ionization cross sections from the ground and first excited states are calculated as a function of photon energy. Calculations are performed using the frozen-core Hartree-Fock and also the model potential approaches and the results are compared. We find that the model potential approach provide results as good as or even slightly better than those by the frozen-core Hartree-Fock approach. We also report the relative ratios of the ionization cross sections by the circularly and linearly polarized laser fields as a function of photon energy, which exhibit clear effects of electron correlations.