Spin Hall magnetoresistance in antiferromagnet/normal metal bilayers

TL;DR

This paper predicts a spin Hall magnetoresistance effect in antiferromagnet/normal metal bilayers, where resistance depends on the Nel order parameter orientation, revealing a new anisotropic spin relaxation mechanism.

Contribution

It introduces the theoretical prediction of spin Hall magnetoresistance in antiferromagnetic bilayers based on a drift-diffusion model, highlighting a novel physical origin.

Findings

Resistance depends on the angle between current and Nel order

Effect similar to ferromagnetic spin Hall magnetoresistance

Origin linked to anisotropic spin relaxation in antiferromagnets

Abstract

We predict the emergence of spin Hall magnetoresistance in a magnetic bilayer composed of a normal metal adjacent to an antiferromagnet. Based on a recently derived drift-diffusion equation, we show that the resistance of the bilayer depends on the relative angle between the direction transverse to the current flow and the N\'eel order parameter. Although this effect presents striking similarities with the spin Hall magnetoresistance recently reported in ferromagnetic bilayers, in the present case its physical origin is attributed to the anisotropic spin relaxation of itinerant spins in the antiferromagnet.