Non-Markovian pure dephasing in a dielectric excited by a few-cycle laser pulse

TL;DR

This paper develops a non-Markovian theory of pure dephasing in solids exposed to ultrashort laser pulses, improving the accuracy of modeling high-harmonic generation and charge carrier dynamics.

Contribution

It introduces a non-Markovian approach that accounts for finite bath cutoff energy, enhancing the modeling of decoherence in ultrafast laser-solid interactions.

Findings

Time-dependent rates accurately reproduce high-harmonic spectra.

Non-Markovian model avoids overestimating charge carrier population.

Improved understanding of decoherence effects in ultrafast phenomena.

Abstract

We develop the theory of pure dephasing in a solid exposed to an ultrashort laser pulse beyond the commonly used Markov approximation. This approach takes into account the finite cutoff energy of the bath and can be applied to both many-particle and phonon environments. With numerical simulations performed with the time-dependent Hartree-Fock equations, we investigate how the excitation probability and high-harmonic generation are described by different models of decoherence. It is shown that the time-dependent rates allow for temporally high dephasing to successfully reproduce the main features of high-harmonics spectrum and avoid an overestimation of the charge carrier population after the pulse, which is a common problem of the Markov approximation.