The effect of electron-electron correlation on the attoclock experiment

TL;DR

This paper explores how electron-electron interactions influence the outcomes of attoclock experiments in Helium, revealing significant effects that can be modeled with a mean field approach and aligning well with single-electron theories.

Contribution

It introduces a semi-classical model that explicitly includes electron-electron correlation and allows selective analysis of different ionic contributions in attoclock experiments.

Findings

Bound electron significantly affects final electron momentum distribution.

Mean field approximation effectively accounts for electron-electron effects.

Results agree with single active electron models.

Abstract

We investigate multi-electron effects in strong-field ionization of Helium using a semi-classical model that, unlike other commonly used theoretical approaches, takes into account electron-electron correlation. Our approach has an additional advantage of allowing to selectively switch off different contributions from the parent ion (such as the remaining electron or the nuclear charge) and thereby investigate in detail how the final electron angle in the attoclock experiment is influenced by these contributions. We find that the bound electron exerts a significant effect on the final electron momenta distribution that can, however, be accounted for by an appropriately selected mean field. Our results show excellent agreement with other widely used theoretical models done within a single active electron approximation.