Quantum optimal control of photoelectron spectra and angular distributions

TL;DR

This paper introduces a method combining optimal control theory with quantum dynamics simulations to enhance specific features in photoelectron spectra and angular distributions, enabling directed electron emission in the XUV regime.

Contribution

It develops a novel approach integrating Krotov's method with time-dependent configuration interaction singles to control photoelectron features.

Findings

Successfully optimized electron emission direction in hydrogen and argon.

Enhanced control over photoelectron angular distributions and spectra.

Demonstrated directed emission in the XUV regime.

Abstract

Photoelectron spectra and photoelectron angular distributions obtained in photoionization reveal important information on e.g. charge transfer or hole coherence in the parent ion. Here we show that optimal control of the underlying quantum dynamics can be used to enhance desired features in the photoelectron spectra and angular distributions. To this end, we combine Krotov's method for optimal control theory with the time-dependent configuration interaction singles formalism and a splitting approach to calculate photoelectron spectra and angular distributions. The optimization target can account for specific desired properties in the photoelectron angular distribution alone, in the photoelectron spectrum, or in both. We demonstrate the method for hydrogen and then apply it to argon under strong XUV radiation, maximizing the difference of emission into the upper and lower hemispheres, in order to realize directed electron emission in the XUV regime.