Thermal rectification in anharmonic chains under an energy-conserving noise

TL;DR

This paper demonstrates that thermal rectification in anharmonic chains can be maintained in the thermodynamic limit by introducing an energy-conserving noise, resolving a discrepancy between theoretical models and experimental observations.

Contribution

It introduces an energy-conserving noise mechanism that preserves thermal rectification in large systems, unlike previous models where rectification vanished.

Findings

Rectification remains finite with non-zero noise rate λ

Energy-conserving noise stabilizes rectification in the thermodynamic limit

Application to a classical harmonic chain with quartic pinning potential

Abstract

Systems in which the heat flux depends on the direction of the flow are said to present thermal rectification. This effect has attracted much theoretical and experimental interest in recent years. However, in most theoretical models the effect is found to vanish in the thermodynamic limit, in disagreement with experiment. The purpose of this paper is to show that the rectification may be restored by including an energy-conserving noise which randomly flips the velocity of the particles with a certain rate $\lambda$. It is shown that as long as $\lambda$ is non-zero, the rectification remains finite in the thermodynamic limit. This is illustrated in a classical harmonic chain subject to a quartic pinning potential (the $\Phi^4$ model) and coupled to heat baths by Langevin equations.