Theory of Auger decay by laser-dressed atoms

TL;DR

This paper develops an ab initio quantum dynamical model for Auger decay in laser-dressed atoms, incorporating strong-field effects on continuum electrons and applying it to krypton, revealing how laser fields influence Auger electron spectra.

Contribution

It introduces a novel formalism combining ab initio quantum dynamics with laser dressing effects for Auger decay, solved analytically in an essential-states model.

Findings

The theory accurately predicts Auger electron spectra under laser influence.

Laser fields modify the Auger decay process and electron emission spectra.

The model demonstrates convergence and applicability to krypton atom decay processes.

Abstract

We devise an ab initio formalism for the quantum dynamics of Auger decay by laser-dressed atoms which are inner-shell ionized by extreme ultraviolet (XUV) light. The optical dressing laser is assumed to be sufficiently weak such that ground-state electrons are neither excited nor ionized by it. However, the laser has a strong effect on continuum electrons which we describe in strong-field approximation with Volkov waves. The XUV light pulse has a low peak intensity and its interaction is treated as a one-photon process. The quantum dynamics of the inner-shell hole creation with subsequent Auger decay is given by equations of motion (EOMs). For this paper, the EOMs are simplified in terms of an essential-states model which is solved analytically and averaged over magnetic subshells. We apply our theory to the M_4,5 N_1 N_2,3 Auger decay of a 3d hole in a krypton atom. The orbitals are approximated by scaled hydrogenic wave functions. A single attosecond pulse produces 3d vacancies which Auger decay in the presence of an 800nm laser with an intensity of 10^13 W / cm^2. We compute the Auger electron spectrum and assess the convergence of the various quantities involved.