Crossover between spin swapping and Hall effect in metallic systems

TL;DR

This paper explores the theoretical crossover between spin Hall effect and spin swapping in metallic systems, revealing their different dependencies on spin-orbit coupling and disorder, and proposing experimental setups.

Contribution

It introduces a unified theoretical framework for spin Hall and spin swapping effects, highlighting their distinct behaviors and potential for spin swapping to surpass spin Hall effect.

Findings

Spin swapping can exceed spin Hall effect under certain conditions.

Different dependencies of spin Hall and spin swapping on spin-orbit coupling.

Proposed experimental setups for observing spin swapping in metals.

Abstract

We theoretically study the crossover between spin Hall effect and spin swapping, a recently predicted phenomenon that consists in the interchange between the current flow and its spin polarization directions [Lifshits and Dyakonov, Phys. Rev. Lett. 103, 186601 (2009)]. Using a tight-binding model with spin-orbit coupled disorder, spin Hall effect, spin relaxation and spin swapping are treated on equal footing. We demonstrate that spin Hall effect and spin swapping present very different dependences as a function of the spin-orbit coupling and disorder strengths. As a consequence, we show that spin swapping may even exceed spin Hall effect. Three set-ups are proposed for the experimental observation of the spin swapping effect in metals.