Heat transfer in a nonequilibrium spin-boson model: A perturbative approach

TL;DR

This paper develops a perturbative analytical method to study heat transfer in a nonequilibrium spin-boson model, providing insights into thermal conductance at low temperatures and weak coupling.

Contribution

It introduces a novel perturbative approach combining a unitary transformation and resolvent expansion for analyzing heat transport in the model.

Findings

Analytical expressions for heat current and thermal conductance are derived.

The method accurately describes heat transfer in the weak-coupling, low-temperature regime.

Results compare favorably with Green's function and equation of motion methods.

Abstract

We investigate the heat transport in a nonequilibrium spin-boson model, where a two level system bridging two harmonic reservoirs at different temperatures, by employing a unitary transformation along with a resolvent operator expansion technique. Analytical expressions of the heat current and the thermal conductance of this model are obtained. Compared with the performances of other methods, namely, the nonequilibrium Green's function method and the equation of motion formulation, our approach provides a reasonable description of heat transfer properties of the nonequilibrium spin-boson model for the weak-coupling region at low temperature.