Intrinsic spin-orbit torque arising from Berry curvature in metallic-magnet/Cu-oxide interface

TL;DR

This paper demonstrates an intrinsic damping-like spin-orbit torque in metallic-magnet/CuO_x heterostructures driven by Berry curvature, with interface oxidation controlling the SOT characteristics, advancing understanding of spin-orbit physics.

Contribution

It reveals a large damping-like SOT from Berry curvature in heterostructures without bulk spin-orbit effects, and shows interface oxidation tuning the SOT sign and magnitude.

Findings

Damping-like SOT is an order of magnitude larger than field-like SOT.

The SOT arises from Berry curvature effects, not bulk spin-orbit coupling.

Interface oxidation level controls the sign and strength of the field-like SOT.

Abstract

We report the observation of the intrinsic damping-like spin-orbit torque (SOT) arising from the Berry curvature in metallic-magnet/CuO$_x$ heterostructures. We show that a robust damping-like SOT, an order of magnitude larger than a field-like SOT, is generated in the heterostructure despite the absence of the bulk spin-orbit effect in the CuO$_x$ layer. Furthermore, by tuning the interface oxidation level, we demonstrate that the field-like SOT changes drastically and even switches its sign, which originates from oxygen modulated spin-dependent disorder. These results provide an important information for fundamental understanding of the physics of the SOTs.