Ballistic magneto-thermal transport in a Heisenberg spin chain at low temperatures

TL;DR

This paper investigates ballistic thermal transport in a low-temperature Heisenberg spin chain, deriving analytical transmission coefficients and demonstrating control of spin-wave propagation via magnetic field and coupling adjustments.

Contribution

It provides explicit analytical expressions for thermal transmission in a spin chain, validated against Green's function results, and explores control mechanisms for spin-wave transport.

Findings

Transmission coefficient oscillates with thermal wave frequency

Thermal transmission depends on intrachain coupling, chain length, and magnetic field

Adjusting coupling and magnetic field can manipulate spin-wave propagation

Abstract

We study ballistic thermal transport in Heisenberg spin chain with nearest-neighbor ferromagnetic interactions at low temperatures. Explicit expressions for transmission coefficients are derived for thermal transport in a periodic spin chain of arbitrary junction length by a spin-wave model. Our analytical results agree very well with the ones from nonequilibrium Green's function method. Our study shows that the transmission coefficient oscillates with the frequency of thermal wave. Moreover, the thermal transmission shows strong dependence on the intrachain coupling, the length of the spin chain, and the external magnetic field. The results demonstrate the possibility of manipulating spin-wave propagation and magnetothermal conductance in the spin-chain junction by adjusting the intrachain coupling and/or the external magnetic field.