Intrinsic magnetoresistance in metal films on ferromagnetic insulators

TL;DR

This paper predicts a new type of magnetoresistance caused by interfacial Rashba spin-orbit coupling in metal|ferromagnetic insulator bilayers, which depends on film thickness and can be distinguished from bulk effects.

Contribution

It introduces a theoretical prediction of interfacial Rashba-induced magnetoresistance and proposes a method to distinguish it from bulk spin Hall magnetoresistance.

Findings

Magnetoresistance depends on the angle between current and magnetization.

It varies with metal film thickness, indicating an interfacial origin.

The phenomenon is similar to spin Hall magnetoresistance but has a distinct thickness dependence.

Abstract

We predict a magnetoresistance induced by the interfacial Rashba spin-orbit coupling in normal metal|ferromagnetic insulator bilayer. It depends on the angle between current and magnetization directions identically to the "spin Hall magnetoresistance" mechanism caused by a combined action of spin Hall and inverse spin Hall effects. Due to the identical phenomenology it is not obvious whether the magnetoresistance reported by Nakayama et al. is a bulk metal or interface effect. The interfacial Rashba induced magnetoresistance may be distinguished from the bulk metal spin Hall magnetoresistance by its dependence on the metal film thickness.