Asymmetric Heat Flow in Mesoscopic Magnetic System

TL;DR

This paper investigates asymmetric heat flow in a small coupled magnetic system with gapped and gapless chains, revealing current asymmetry due to local equilibrium effects, analyzed using Keldysh Green functions.

Contribution

It introduces a realistic model showing heat flow asymmetry in mesoscopic magnetic systems, supported by a phenomenological explanation.

Findings

Asymmetry of heat current depends on reservoir temperature configurations.

Local equilibrium at contact points causes the observed asymmetry.

The setup is experimentally feasible and relevant.

Abstract

The characteristics of heat flow in a coupled magnetic system are studied. The coupled system is composed of a gapped chain and a gapless chain. The system size is assumed to be quite small so that the mean free path is comparable to it. When the parameter set of the temperatures of reservoirs is exchanged, the characteristics of heat flow are studied with the Keldysh Green function technique. The asymmetry of current is found in the presence of a local equilibrium process at the contact between the magnetic systems. The present setup is realistic and such an effect will be observed in real experiments. We also discuss the simple phenomenological explanation to obtain the asymmetry.