Thermoelectric spin transfer in textured magnets

TL;DR

This paper explores how magnetic textures influence charge and energy transport in quasi-1D magnets, revealing reciprocal effects and introducing a viscous coupling that impacts thermally driven domain wall motion.

Contribution

It introduces a new viscous coupling in the LLG equation and demonstrates reciprocal effects between energy currents and magnetic textures, advancing understanding of thermoelectric spin transfer.

Findings

Energy flows can induce spin torques similar to charge currents.

A new viscous coupling affects thermally induced domain wall motion.

Magnetic textures can generate energy flows analogous to electromotive forces.

Abstract

We study charge and energy transport in a quasi-1D magnetic wire in the presence of magnetic textures. The energy flows can be expressed in a fashion similar to charge currents, leading to new energy-current induced spin torques. In analogy to charge currents, we can identify two reciprocal effects: spin-transfer torque on the magnetic order parameter induced by energy current and the Berry-phase gauge field induced energy flow. In addition, we phenomenologically introduce new $\beta-$like viscous coupling between magnetic dynamics and energy current into the LLG equation, which originates from spin mistracking of the magnetic order. We conclude that the new viscous term should be important for the thermally induced domain wall motion. We study the interplay between charge and energy currents and find that many of the effects of texture motion on the charge currents can be replicated with respect to energy currents. For example, the moving texture can lead to energy flows which is an analogue of the electromotive force in case of charge currents. We suggest a realization of cooling effect by magnetic texture dynamics.