Time delay in valence shell photoionization of noble gas atoms

TL;DR

This paper calculates valence shell photoionization time delays in noble gases using the random phase approximation, comparing results with experiments and exploring atomic physics insights via attosecond measurements.

Contribution

It introduces a systematic theoretical approach to map photoionization time delays across photon energies in noble gases, aiding fundamental atomic physics understanding.

Findings

Good agreement with experimental time delay measurements in Ne and Ar.

Systematic mapping reveals energy-dependent features of atomic photoionization delays.

Highlights potential of attosecond techniques to probe atomic physics phenomena.

Abstract

We use the non-relativistic random phase approximation with exchange to perform calculations of valence shell photoionization of Ne, Ar, Kr and Xe from their respective thresholds to photon energy of 200 eV. The energy derivative of the complex phase of the photoionization matrix elements is converted to the photoelectron group delay that can be measured in attosecond streaking or two-photon transitions interference experiments. Comparison with reported time delay measurements in Ne and Ar at a few selected photon energies is made. Systematic mapping of time delay across a wide range of photon energies in several atomic targets allows to highlight important aspects of fundamental atomic physics that can be probed by attosecond time delay measurements.