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.
@article{arxiv.1903.07223,
title = {Theory of spin transport through antiferromagnetic insulator},
author = {Gen Tatara and Christian Ortiz Pauyac},
journal= {arXiv preprint arXiv:1903.07223},
year = {2019}
}