Quantum thermal transport from classical molecular dynamics

TL;DR

This paper introduces a semi-classical method using a generalized Langevin equation with quantum Bose-Einstein noise to accurately simulate quantum thermal transport in molecular dynamics, capturing both ballistic and diffusive regimes.

Contribution

It presents a novel approach that combines classical molecular dynamics with quantum statistics to model thermal transport across different regimes.

Findings

Accurately models quantum ballistic and classical diffusive transport.

Demonstrates crossover from ballistic to diffusive behavior in a 1D model.

Provides asymptotically exact results in both low and high-temperature regimes.

Abstract

Using a generalized Langevin equation of motion, quantum ballistic thermal transport is obtained from classical molecular dynamics. This is possible because the heat baths are represented by random noises obeying quantum Bose-Einstein statistics. The numerical method gives asymptotically exact results in both the low-temperature ballistic transport regime and high-temperature strongly nonlinear classical regime. The method can be thought of as a semi-classical approximation to the quantum transport problem. A one-dimensional quartic on-site model is used to demonstrate the crossover from ballistic to diffusive thermal transport.