Real-Time Out-of-Equilibrium Quantum Dynamics in Disordered Materials

TL;DR

This paper introduces a linear-scaling numerical method based on Chebyshev expansion to study nonequilibrium electron dynamics in disordered materials, enabling analysis of large systems and complex phenomena.

Contribution

The paper presents a novel, scalable computational approach for simulating out-of-equilibrium quantum dynamics in disordered systems of arbitrary size and complexity.

Findings

Disorder can enhance optical absorption in graphene.

Interplay of light, anisotropy, and disorder can be useful for sensing.

Method validated on saturable optical absorption in graphene.

Abstract

We report a linear-scaling numerical method for exploring nonequilibrium electron dynamics in systems of arbitrary complexity. Based on the Chebyshev expansion of the time evolution of the single-particle density matrix, the method gives access to nonperturbative excitation and relaxation phenomena in models of disordered materials with sizes on the experimental scale. After validating the method by applying it to saturable optical absorption in clean graphene, we uncover that disorder can enhance absorption in graphene and that the interplay between light, anisotropy, and disorder in nanoporous graphene might be appealing for sensing applications. Beyond the optical properties of graphene-like materials, the method can be applied to a wide range of large-area materials and systems with arbitrary descriptions of defects and disorder.