XUV+IR photoionization of argon atoms: selection of sideband orders

TL;DR

This paper theoretically investigates how symmetry and periodicity in XUV+IR photoionization of argon atoms influence the selection of sideband orders, revealing that only specific orders are favored due to destructive interference effects.

Contribution

It introduces a symmetry-based approach to predict sideband order selection in atomic ionization under combined XUV and IR fields, simplifying the analysis to a single or half IR cycle.

Findings

Selection rules derived from symmetry cancel certain sidebands.

Photoelectron spectrum can be described from a single IR cycle.

Analysis of four geometrical arrangements of polarization and momentum.

Abstract

We present a theoretical study of atomic ionization due to an XUV pulse in the presence of an infrared laser. Within the strong field approximation and considering the periodicity and symmetry of the transition matrix we show that the photoelectron spectrum can be described from the contribution during only one (or half) infrared cycle. These symmetry and periodicity properties impress selection rules which destructively cancel certain sideband orders favoring others. In particular, we analyze the photoionization of Argon in four geometrical arrangements of the polarization vector and the photoelectron momentum direction.