Real-time GW-Ehrenfest-Fan-Migdal method for nonequilibrium 2D materials

TL;DR

This paper introduces a novel ab initio many-body method for real-time quantum simulations of 2D materials, capturing complex electron-nuclear interactions and coherence effects to better understand ultrafast dynamics in systems like MoS₂.

Contribution

It presents an advanced, parameter-free ab initio method that accounts for quantum coherence and non-Markovian effects in real-time simulations of 2D materials.

Findings

Demonstrates multivalley dynamics in MoS₂ monolayer

Provides insight into coherent-to-incoherent crossover

Elucidates roles of microscopic and collective excitations

Abstract

Quantum simulations of photoexcited low-dimensional systems are pivotal for understanding how to functionalize and integrate novel two-dimensional (2D) materials in next-generation optoelectronic devices. First principles predictions are extremely challenging due to the simultaneous interplay of light-matter, electron-electron and electron-nuclear interactions. We here present an advanced ab initio many-body method which accounts for quantum coherence and non-Markovian effects while treating electrons and nuclei on equal footing, thereby preserving fundamental conservation laws like the total energy. The impact of this advancement is demonstrated through real-time simulations of the complex multivalley dynamics in a molybdenum disulfide (MoS$_{2}$) monolayer pumped above gap. Within a single framework we provide a parameter-free description of the coherent-to-incoherent crossover, elucidating the role of microscopic and collective excitations in the dephasing and thermalization processes.