Mixed quantum-classical modeling of exciton-phonon scattering in solids: Application to optical linewidths of monolayer MoS2

TL;DR

This paper develops a mixed quantum-classical approach to model exciton-phonon interactions in solids, successfully predicting optical linewidths in monolayer MoS2 that align with experimental data, advancing understanding of non-Markovian dynamics.

Contribution

It introduces a novel mixed quantum-classical framework for exciton-phonon scattering, integrating ab initio parametrization and zone truncation techniques for accurate linewidth predictions.

Findings

Asymptotic linewidths agree with experiments across temperatures.

The framework effectively captures non-Markovian and microscopic dynamics.

Parameter variations help in understanding size effects on linewidths.

Abstract

We present a mixed quantum-classical framework for the microscopic and non-Markovian modeling of exciton-phonon scattering in solid-state materials, and apply it to calculate the optical linewidths of monolayer MoS2. Within this framework, we combine reciprocal-space mixed quantum-classical dynamics with models for the quasiparticle band structure as well as the electron-hole and carrier-phonon interactions, parametrized against ab initio calculations, although noting that a direct interfacing with ab initio calculations is straightforward in principle. We introduce various parameters for truncating the Brillouin zone to select regions of interest. Variations of these parameters allow us to determine linewidths in the limit of asymptotic material sizes. Obtained asymptotic linewidths are found to agree favorably with experimental measurements across a range of temperatures. As such, our framework establishes itself as a promising route towards unraveling the non-Markovian and microscopic principles governing the nonadiabatic dynamics of solids.