Probing Electron Correlation via Attosecond XUV Pulses in the Two-Photon Double Ionization of Helium

TL;DR

This paper uses attosecond XUV pulses to explore electron-electron correlations in helium's two-photon double ionization, revealing detailed electron dynamics and interaction regimes through time-dependent calculations.

Contribution

It demonstrates how attosecond pulses can induce and probe electron correlations and momentum distributions in helium's double ionization, advancing experimental and theoretical understanding.

Findings

Identification of Wannier ridge break-up regions

Observation of post-collision interaction effects

Demonstration of angular and energy correlation probing

Abstract

Recent experimental developments of high-intensity, short-pulse XUV light sources are enhancing our ability to study electron-electron correlations. We perform time-dependent calculations to investigate the so-called "sequential" regime (photon energy above 54.4 eV) in the two-photon double ionization of helium. We show that attosecond pulses allow to induce and probe angular and energy correlations of the emitted electrons. The final momentum distribution reveals regions dominated by the Wannier ridge break-up scenario and by post-collision interaction.