Quantum mechanical scattering on time-dependent potentials using nonequilibrium Green's functions

TL;DR

This paper demonstrates how time-dependent nonequilibrium Green's functions (TDNEGF) can effectively model quantum scattering on localized, time-varying potentials, with applications to laser-electron interactions.

Contribution

It introduces a numerical framework using TDNEGF for quantum scattering with arbitrary time-dependent potentials, emphasizing its flexibility and physical interpretability.

Findings

Effective modeling of laser-electron interactions

Numerical methods handle arbitrary space and time dependence

Clear physical interpretation of scattering processes

Abstract

Time-dependent nonequilibrium Green's functions (TDNEGF) are shown to provide a flexible, effective tool for the description of quantum mechanical single particle scattering on a spatially localized, time-dependent potential. Focusing on numerical methods, arbitrary space and time dependence of the potential can be treated, provided it is zero before an initial time instant. In this case, appropriate version of the Dyson and Keldysh equations lead to a transparent description with clear physical interpretation. The interaction of a short laser pulse and an electron propagating initially in free space is discussed as an example.