Propensity rules and interference effects in laser-assisted photoionization of helium and neon

TL;DR

This paper studies laser-assisted photoionization in helium and neon, revealing how propensity rules and interference effects shape the angular distributions of photoelectrons, with implications for attosecond science.

Contribution

It introduces an extit{ab initio} method to interpret angle-resolved spectra using propensity rules and interference effects, enhancing understanding of photoionization dynamics.

Findings

Shape of distributions explained by propensity rules and interference effects

Difference between absorption and emission hidden in neon's first sideband

Insights into minima formation in angular distributions and photoionization delays

Abstract

We investigate the angle-resolved photoelectron spectra from laser-assisted photoionization for helium and neon atoms using an \textit{ab initio} method based on time-dependent surface flux and configuration interaction singles. We find that the shape of the distributions can be interpreted using a propensity rule, an intrinsic difference in the absorption and emission processes, as well as interference effects between multiple paths to the final angular momentum state. In neon we find that the difference between absorption and emission is hidden in the first sideband due to the multiple competing $m$ channels. Together, this aids the understanding of the formation of minima in the angular distributions, which can be transferred to an improved understanding on photoionization time delays in attosecond science.