Hanle Magnetoresistance in Thin Metal Films with Strong Spin-Orbit Coupling

TL;DR

This paper reports a new type of magnetoresistance in thin Pt and Ta films caused by the Hanle effect, providing a simple method to study charge-spin coupling in metals with strong spin-orbit interaction.

Contribution

It introduces Hanle magnetoresistance in non-magnetic metals as a novel phenomenon for analyzing spin-charge interactions.

Findings

Hanle magnetoresistance observed in Pt and Ta films.

Magnetoresistance increases with magnetic field due to spin Hall effect.

Resembles spin Hall magnetoresistance but does not require ferromagnetic insulators.

Abstract

We report measurements of a new type of magnetoresistance in Pt and Ta thin films. The spin accumulation created at the surfaces of the film by the spin Hall effect decreases in a magnetic field because of the Hanle effect, resulting in an increase of the electrical resistance as predicted by Dyakonov [PRL 99, 126601 (2007)]. The angular dependence of this magnetoresistance resembles the recently discovered spin Hall magnetoresistance in Pt/Y3Fe5O12 bilayers, although the presence of a ferromagnetic insulator is not required. We show that this Hanle magnetoresistance is an alternative, simple way to quantitatively study the coupling between charge and spin currents in metals with strong spin-orbit coupling.