Spin Hall Magnetoresistance Induced by a Non-Equilibrium Proximity Effect

TL;DR

This paper demonstrates anisotropic magnetoresistance in Pt|Y3Fe5O12 bilayers caused by spin Hall effects, revealing a non-equilibrium proximity effect that influences resistance despite the insulating nature of Y3Fe5O12.

Contribution

It introduces the concept of spin Hall magnetoresistance, showing how spin Hall effects can induce magnetoresistance without equilibrium magnetization at the interface.

Findings

Magnetoresistance persists with a Cu spacer, indicating a non-equilibrium origin.

The effect is due to combined direct and inverse spin Hall effects.

Y3Fe5O12 remains electrically insulating, ruling out equilibrium magnetization contributions.

Abstract

We report anisotropic magnetoresistance in Pt|Y3Fe5O12 bilayers. In spite of Y3Fe5O12 being a very good electrical insulator, the resistance of the Pt layer reflects its magnetization direction. The effect persists even when a Cu layer is inserted between Pt and Y3Fe5O12, excluding the contribution of induced equilibrium magnetization at the interface. Instead, we show that the effect originates from concerted actions of the direct and inverse spin Hall effects and therefore call it "spin Hall magnetoresistance."