Simulation of attosecond streaking of electrons emitted from a tungsten surface

TL;DR

This paper presents a microscopic simulation of attosecond streaking in tungsten, reproducing experimental spectra and identifying factors contributing to emission delays of core electrons.

Contribution

It introduces a classical transport theory simulation that accurately reproduces streaking images and elucidates the origins of emission delays in attosecond photoemission.

Findings

Simulation matches experimental spectra and streaking images.

Identifies key factors causing emission delay: depth, scattering, dispersion.

Delay times are near the lower bound of experimental data.

Abstract

First time-resolved photoemission experiments employing attosecond streaking of electrons emitted by an XUV pump pulse and probed by a few-cycle NIR pulse found a time delay of about 100 attoseconds between photoelectrons from the conduction band and those from the 4f core level of tungsten. We present a microscopic simulation of the emission time and energy spectra employing a classical transport theory. Emission spectra and streaking images are well reproduced. Different contributions to the delayed emission of core electrons are identified: larger emission depth, slowing down by inelastic scattering processes, and possibly, energy dependent deviations from the free-electron dispersion. We find delay times near the lower bound of the experimental data.