Enhancement of magnetic spin Hall angle by extrinsic surface roughness

TL;DR

This paper proposes that extrinsic surface roughness can significantly enhance the magnetic spin Hall angle, improving the efficiency of spin current conversion in spintronic devices.

Contribution

It introduces a novel mechanism where surface roughness increases the magnetic spin Hall angle, advancing the understanding of spin current manipulation.

Findings

Surface roughness enhances the magnetic spin Hall angle.

The effect is more pronounced when roughness-to-thickness ratio is high.

Potential to improve charge-to-spin device efficiency.

Abstract

The magnetic spin Hall effect arises from a reactive counterpart of the dissipative spin response that is responsible for the ordinary spin Hall effect. This interpretation is supported by the dependence of spin Hall effect signals on the reversal of magnetic order parameters and can be explained in terms of the symmetries of well-defined linear response functions. This proposal has enabled the generation and manipulation of spin currents electrically. In terms of conversion efficiency, the spin Hall angle is a key parameter used to characterize a material's ability to convert spin currents to charge currents and vice versa. Consequently, there is an ongoing effort to identify mechanisms that can increase the spin Hall angle. In theis work, it is proposed a mechanism based on extrinsic surface roughness, which enhances the magnetic spin Hall angle when the ratio of roughness to thickness is high. This mechanism represents an important discovery that will advance the development of charge-to-spin devices.