Spin rectification in thermally driven XXZ spin chain via the spin-Seebeck effect

TL;DR

This paper investigates spin-current rectification in a thermal-driven XXZ spin chain, revealing size-dependent oscillations and magnetic field tunability, highlighting potential for spin device applications.

Contribution

It introduces a model combining the spin-Seebeck effect with a nonequilibrium Redfield approach to analyze spin rectification in XXZ chains, emphasizing low-temperature oscillations and magnetic control.

Findings

Spin-current rectification exhibits size-dependent oscillations at low temperatures.

External magnetic fields enable high tunability of rectification.

Magnetic insulators described by the XXZ model are promising for spin devices.

Abstract

We study the phenomenon of spin-current rectification in a one-dimensional XXZ spin chain in the presence of a thermal drive. In our model a pure spin current is generated by a temperature difference between two harmonic heat baths which in turn creates a spin voltage via the spin-Seebeck effect. Along with a local spin-current operator definition and the nonequilibrium modified Redfield solution we study the spin-rectification ratio as a function of system size and external magnetic field. Intriguing effects are observed at low temperatures such as oscillations with system size and high range of tunability with external magnetic field making magnetic insulators, which are well described by the XXZ model, ideal candidates to build spin devices based on rectification.