Giant Spin Hall Effect Induced by Skew Scattering from Bismuth Impurities inside Thin Film CuBi Alloys

TL;DR

This paper demonstrates that introducing bismuth impurities into copper induces a giant, negative spin Hall effect with a large spin Hall angle, explained by a resonant scattering model, advancing spintronic material understanding.

Contribution

The study reveals a significant spin Hall effect in CuBi alloys caused by Bi impurities, supported by a new 3D finite element spin transport analysis and resonant scattering theory.

Findings

Giant negative spin Hall angle of -0.24 in CuBi alloys.

Spin Hall effect induced by Bi impurities is explained by resonant scattering.

New 3D finite element model effectively analyzes spin transport in alloys.

Abstract

We demonstrate that a giant spin Hall effect (SHE) can be induced by introducing a small amount of Bi impurities in Cu. Our analysis based on a new 3-dimensional finite element treatment of spin transport shows that the sign of the SHE induced by the Bi impurities is negative and its spin Hall (SH) angle amounts to -0.24. Such a negative large SH angle in CuBi alloys can be explained by applying the resonant scattering model proposed by Fert and Levy [Phys. Rev. Lett. 106, 157208 (2011)] to 6p impurities.