Current-induced magnetization reversal in (Ga,Mn)(Bi,As) epitaxial layer with perpendicular magnetic anisotropy

TL;DR

This study demonstrates that adding bismuth to (Ga,Mn)As enhances spin-orbit torque efficiency, significantly reducing the current needed for magnetization reversal, which is promising for spintronic memory and logic devices.

Contribution

It introduces (Ga,Mn)(Bi,As) as a new material with improved current-induced magnetization reversal efficiency due to increased spin-orbit coupling.

Findings

Bi addition enhances spin-orbit torque efficiency.

Threshold current density for reversal is significantly reduced.

Magnetization reversal is confirmed via anomalous Hall effect measurements.

Abstract

Pulsed current-induced magnetization reversal is investigated in the layer of (Ga,Mn)(Bi,As) dilute ferromagnetic semiconductor (DFS) epitaxially grown under tensile misfit strain causing perpendicular magnetic anisotropy in the layer. The magnetization reversal, recorded through measurements of the anomalous Hall effect, appearing under assistance of a static magnetic field parallel to the current, is interpreted in terms of the spin-orbit torque mechanism. Our results demonstrate that an addition of a small fraction of heavy Bi atoms, substituting As atoms in the prototype DFS (Ga,Mn)As and increasing the strength of spin-orbit coupling in the DFS valence band, significantly enhances the efficiency of current-induced magnetization reversal thus reducing considerably the threshold current density necessary for the reversal. Our findings are of technological importance for applications to spin-orbit torque-driven nonvolatile memory and logic elements.