Thermal transport in one-dimensional spin heterostructures

TL;DR

This paper investigates heat transport in a one-dimensional quantum spin chain with inhomogeneous reservoirs, revealing rectification effects under finite magnetic fields using non-equilibrium Green's functions.

Contribution

It introduces a method to analyze heat flow in inhomogeneous spin chains with fermionic mapping and demonstrates rectification phenomena under magnetic fields.

Findings

Heat currents depend on model parameters.

Rectification effects occur with finite magnetic fields.

Fermionic mapping enables analytical solutions.

Abstract

We study heat transport in a one-dimensional inhomogeneous quantum spin 1/2 system. It consists of a finite-size XX spin chain coupled at its ends to semi-infinite XX and XY chains at different temperatures, which play the role of heat and spin reservoirs. After using the Jordan-Wigner transformation we map the original spin Hamiltonian into a fermionic Hamiltonian, which contains normal and pairing terms. We find the expressions for the heat currents and solve the problem with a non-equilibrium Green's function formalism. We analyze the behavior of the heat currents as functions of the model parameters. When finite magnetic fields are applied at the two reservoirs, the system exhibits rectification effects in the heat flow.