# Domain wall motion by localized temperature gradients

## TL;DR

This paper investigates how localized temperature gradients can induce magnetic domain wall motion in Permalloy nanostrips, analyzing various contributing mechanisms and comparing theoretical insights with experimental conditions.

## Contribution

The study isolates and compares entropic torque, magnonic spin transfer torque, and dipolar field effects on thermally driven domain wall motion in a detailed theoretical framework.

## Key findings

- Magnonic spin transfer torque significantly influences DW motion.
- A thermally induced dipolar field acts as a driving force.
- Edge roughness affects the efficiency of thermally induced DW motion.

## Abstract

Magnetic domain wall (DW) motion induced by a localized Gaussian temperature profile is studied in a Permalloy nanostrip within the framework of the stochastic Landau-Lifshitz-Bloch equation. The different contributions to thermally induced DW motion, entropic torque and magnonic spin transfer torque, are isolated and compared. The analysis of magnonic spin transfer torque includes a description of thermally excited magnons in the sample. A third driving force due to a thermally induced dipolar field is found and described. Finally, thermally induced DW motion is studied under realistic conditions by taking into account the edge roughness. The results give quantitative insights into the different mechanisms responsible for domain wall motion in temperature gradients and allow for comparison with experimental results.