Influence of Joule heating on current-induced domain wall depinning

TL;DR

This paper investigates how Joule heating affects current-induced domain wall depinning in Permalloy nanostrips, revealing its significant impact on depinning behavior and phase diagrams, which enhances understanding beyond spin transfer torque effects.

Contribution

It introduces a self-consistent model coupling magnetization dynamics with heat transport, highlighting Joule heating's role in domain wall depinning beyond traditional spin torque explanations.

Findings

Joule heating reduces the critical depinning field.

Joule heating can temporarily destroy ferromagnetic order.

Pinning-depinning phase diagrams are similar for both current polarities when heating is considered.

Abstract

The domain wall depinning from a notch in a Permalloy nanostrip on top of a ${\rm SiO_2/Si}$ substrate is studied theoretically under application of static magnetic fields and the injection of short current pulses. The influence of Joule heating on current-induced domain wall depinning is explored self-consistently by coupling the magnetization dynamics in the ferromagnetic strip to the heat transport throughout the system. Our results indicate that Joule heating plays a remarkable role in these processes, resulting in a reduction in the critical depinning field and/or in a temporary destruction of the ferromagnetic order for typically injected current pulses. In agreement with experimental observations, similar pinning-depinning phase diagrams can be deduced for both current polarities when the Joule heating is taken into account. These observations, which are incompatible with the sole contribution of spin transfer torques, provide a deeper understanding of the physics underlying these processes and establish the real scope of the spin transfer torque. They are also relevant for technological applications based on current-induced domain-wall motion along soft strips.