A single-electron approach for many-electron dynamics in high-order harmonic generation

TL;DR

This paper introduces a new single-electron method for simulating many-electron dynamics in high-order harmonic generation, simplifying complex correlated electron interactions into a manageable single-electron framework.

Contribution

The authors develop an ab-initio single-electron approach that accurately reproduces harmonic spectra by approximating the many-electron wavefunction with a product of marginal and conditional wavefunctions.

Findings

Accurately reproduces high-order harmonic spectra for a model Helium atom.

Uses an adiabatic approximation to generate a one-electron potential.

Simplifies complex electron correlations into a single-electron Schrödinger equation.

Abstract

We present a novel ab-initio single-electron approach to correlated electron dynamics in strong laser fields. By writing the electronic wavefunction as a product of a marginal one-electron wavefunction and a conditional wavefunction, we show that the exact harmonic spectrum can be obtained from a single-electron Schr\"odinger equation. To obtain the one-electron potential in practice, we propose an adiabatic approximation, i.e. a potential is generated that depends only on the position of one electron. This potential, together with the laser interaction, is then used to obtain the dynamics of the system. For a model Helium atom in a laser field, we show that by using our approach, the high-order harmonic generation spectrum can be obtained to a good approximation.