Thermal conduction in molecular chains: Non-Markovian effects

TL;DR

This study investigates how non-Markovian reservoirs influence heat conduction in molecular chains, revealing that reservoir spectral properties significantly affect heat current, with potential for anharmonic chains to outperform harmonic ones under certain conditions.

Contribution

It demonstrates the impact of non-Markovian effects on heat conduction in molecular chains and introduces a simple model to explain the complex distance dependence observed.

Findings

Non-Markovian reservoirs alter heat current behavior.

Anharmonic chains can surpass harmonic chains in heat flux.

A single-mode model captures the observed distance dependence.

Abstract

We study the effect of non-Markovian reservoirs on the heat conduction properties of short to intermediate size molecular chains. Using classical molecular dynamics simulations, we show that the distance dependence of the heat current is determined not only by the molecular properties, rather it is also critically influenced by the spectral properties of the heat baths for both harmonic and anharmonic molecular chains. For highly correlated reservoirs the current of an anharmonic chain may exceed the flux of the corresponding harmonic system. Our numerical results are accompanied by a simple single-mode heat conduction model that can capture the intricate distance dependence obtained numerically.