# Theory of Spin Hall Magnetoresistance from a Microscopic Perspective

## TL;DR

This paper develops a microscopic theory for spin Hall magnetoresistance in metals interfaced with magnetic insulators, linking interface parameters to observable resistance effects and predicting complex magnetic field and temperature dependencies.

## Contribution

It introduces a microscopic framework expressing spin-mixing conductances via interface parameters and spin correlations, advancing understanding of spin Hall magnetoresistance phenomena.

## Key findings

- Predicts complex magnetic field and temperature dependence of resistance.
- Provides a microscopic link between interface properties and magnetoresistance.
- Offers explanations for experimental observations in heavy metal/magnetic insulator systems.

## Abstract

We present a theory of the spin Hall magnetoresistance of metals in contact with magnetic insulators. We express the spin-mixing conductances, which govern the phenomenology of the effect, in terms of the microscopic parameters of the interface and the spin-spin correlation functions of the local moments on the surface of the magnetic insulator. The magnetic field and temperature dependence of the spin-mixing conductances leads to a rich behaviour of the resistance due to an interplay between the Hanle effect and spin mixing at the interface. Our theory provides a useful tool for understanding the experiments on heavy metals in contact with magnetic insulators of different kinds, and it predicts striking behaviours of magnetoresistance.