# Theory of spin transport through antiferromagnetic insulator

## TL;DR

This paper develops a theoretical model for spin transport through antiferromagnetic insulators, highlighting the role of magnon correlations and temperature effects in spin diffusion.

## Contribution

It introduces a novel theoretical framework incorporating magnon representation and temperature-dependent damping to describe spin transport in antiferromagnets.

## Key findings

- Spin signal transfer is mediated by ferromagnetic correlations.
- Spin diffusion length peaks near the Ne9el transition temperature.
- High-temperature behavior includes short AF correlations and magnon scattering effects.

## Abstract

A theoretical formulation for spin transport through an antiferromagnetic (AF) insulator is presented in the case driven/detected by direct/inverse spin Hall effect in two heavy metal contacts. The spin signal is shown to be transferred by the ferromagnetic correlation function of the antiferromagnet, which is calculated based on a magnon representation. To cover high temperature regimes, we include an auxiliary field representing short AF correlations and a temperature-dependent damping due to magnon scattering. The diffusion length for spin is long close to the degeneracy of the two AF magnons, and has a maximum as function of temperature near the N\'eel transition.