Attosecond streaking of correlated two-electron transitions in helium

TL;DR

This paper uses ab initio simulations to study attosecond streaking in helium ionization with electron shake-up, revealing detailed electron dynamics and a new delay contribution from electron-electron and field interactions.

Contribution

It provides the first detailed ab initio analysis of correlated two-electron dynamics in attosecond streaking, including a novel delay component from electron-electron and field interplay.

Findings

Streaking spectroscopy reveals detailed time delays in correlated electron emission.

A new contribution to streaking delay arises from electron-electron and field interactions.

Benchmark results for future attosecond experiments on correlated systems.

Abstract

We present fully ab initio simulations of attosecond streaking for ionization of helium accompanied by shake-up of the second electron. This process represents a prototypical case for strongly correlated electron dynamics on the attosecond timescale. We show that streaking spectroscopy can provide detailed information on the Eisenbud-Wigner-Smith time delay as well as on the infrared field dressing of both bound and continuum states. We find a novel contribution to the streaking delay that stems from the interplay of electron-electron and infrared-field interactions in the exit channel. We quantify all the contributions with attosecond precision and provide a benchmark for future experiments.