Attosecond streaking of photoelectrons emitted from metal surfaces

TL;DR

This paper numerically studies attosecond streaking time delays in photoemission from aluminum surfaces, revealing a 100-attosecond delay for core electrons caused by conduction electron screening.

Contribution

It demonstrates the origin of time delays in photoemission from metal surfaces and highlights the role of conduction electrons in screening the streaking field.

Findings

Core electron emission is delayed by 100 attoseconds.

Screening by conduction electrons causes the time offset.

Valence electrons emit earlier than core electrons.

Abstract

We numerically investigate attosecond streaking time delays in the photoemission of valence and 2p core electrons of aluminum surface. We find that electron emission from the core level band is delayed by $\Delta \tau =100$ attoseconds relative to the release of electrons from the valence band. We show that this relative time offset in electron emission is caused by the screening of the streaking laser field by conduction electrons.