# Theory for spin torque in Weyl semimetal with magnetic texture

## TL;DR

This paper presents a theoretical analysis showing that magnetic Weyl semimetals can significantly enhance spin-transfer torque, enabling faster and more energy-efficient control of magnetic domain walls for spintronics applications.

## Contribution

The study derives an analytical expression for spin-transfer torque in Weyl semimetals and demonstrates its potential for improved domain wall velocity and reduced Joule heating.

## Key findings

- Domain wall velocity is an order of magnitude greater than in conventional metals.
- Spin-transfer torque is significantly enhanced due to strong spin-orbit coupling.
- Joule heating dissipation is reduced in thin domain-wall configurations.

## Abstract

The spin-transfer torque is a fundamental physical quantity to operate the spintronics devices such as racetrack memory. We theoretically study the spin-transfer torque and analyze the dynamics of the magnetic domain walls in magnetic Weyl semimetals. Owing to the strong spin-orbit coupling in Weyl semimetals, the spin-transfer torque can be significantly enhanced, because of which they can provide a more efficient means of controlling magnetic textures. We derive the analytical expression of the spin-transfer torque and find that the velocity of the domain wall is one order of magnitude greater than that of conventional ferromagnetic metals. Furthermore, due to the suppression of longitudinal conductivity in the thin domain-wall configuration, the dissipation due to Joule heating for the spin-transfer torque becomes much smaller than that in bulk metallic ferromagnets. Consequently, the fast-control of the domain wall can be achieved with smaller dissipation from Joule heating in the Weyl semimetals as required for application to low-energy-consumption spintronics devices.