Guiding-center motion for electrons in strong laser fields

TL;DR

This paper develops a guiding-center model for electron dynamics in strong laser and Coulomb fields, enabling better understanding of ionization and rescattering processes through averaged equations.

Contribution

It introduces a hierarchy of averaged guiding-center models derived via Lie transforms, improving the qualitative and quantitative description of electron ionization in intense laser fields.

Findings

Models accurately describe ionization channels

Guiding-center models predict rescattering conditions

Comparison shows which models best match full dynamics

Abstract

We consider the dynamics of electrons in combined strong laser and Coulomb fields. Under a timescale separation condition, we reduce this dynamics to a guiding-center framework. More precisely, we derive a hierarchy of models for the guiding-center dynamics based on averaging over the fast motion of the electron using Lie transforms. The reduced models we obtain describe well the different ionization channels, in particular, the conditions under which an electron is rescattered by the ionic core or is directly ionized. The comparison between these models highlights the models which are best suited for a qualitative and quantitative agreement with the parent dynamics.