Current-driven domain wall motion with spin Hall effect: Reduction of threshold current density

TL;DR

This paper theoretically investigates how the spin Hall effect influences current-driven domain wall motion, demonstrating a reduction in threshold current density for depinning and proposing experimental methods to distinguish different spin-transfer torque mechanisms.

Contribution

It introduces a theoretical analysis of the spin Hall effect's role in reducing threshold current for domain wall depinning and suggests experimental differentiation of torque origins.

Findings

Spin Hall effect reduces threshold current density for domain wall depinning.

The damping ratio of domain wall precession is affected by the spin Hall effect.

A method to distinguish spin Hall effect-induced torque from Rashba-induced torque is proposed.

Abstract

We theoretically study the current-driven domain wall motion in the presence of both the spin Hall effect and an extrinsic pinning potential. The spin Hall effect mainly affects the damping ratio of the domain wall precession in the pinning potential. When the pinning potential is not too strong, this results in a significant reduction of a threshold current density for the depinning of a domain wall with certain polarity. We also propose one way to distinguish the spin Hall effect induced spin-transfer torque from the one induced by the Rashba spin-orbit coupling experimentally.