Real-time dynamics of Auger wavepackets and decays in ultrafast charge migration processes

TL;DR

This paper introduces a real-time, first-principles method using nonequilibrium Green's functions to simulate Auger decay and charge migration in molecules, capturing ultrafast electron dynamics with high accuracy.

Contribution

It advances current simulation techniques by enabling first-principles, real-time modeling of Auger processes in complex molecules, including decay dynamics and wavepacket profiles.

Findings

Accurate comparison with 1D grid simulations validates the method.

Predicted asymmetric Auger wavepacket with ripples and long tail.

Method applicable to molecules with tens of active electrons.

Abstract

The Auger decay is a relevant recombination channel during the first few femtoseconds of molecular targets impinged by attosecond XUV or soft X-ray pulses. Including this mechanism in time--dependent simulations of charge--migration processes is a difficult task, and Auger scatterings are often ignored altogether. In this work we present an advance of the current state-of-the-art by putting forward a real--time approach based on nonequilibrium Green's functions suitable for first-principles calculations of molecules with tens of active electrons. To demonstrate the accuracy of the method we report comparisons against accurate grid simulations of one-dimensional systems. We also predict a highly asymmetric profile of the Auger wavepacket, with a long tail exhibiting ripples temporally spaced by the inverse of the Auger energy.