Magnon spin Nernst effect in antiferromagnets

TL;DR

This paper predicts a magnon spin Nernst effect in antiferromagnets, where a temperature gradient induces a spin Hall response mediated by magnons, with theoretical development and application to honeycomb lattice systems.

Contribution

It introduces a linear response theory for magnon-mediated spin Hall effects in antiferromagnets, including conditions for Hall currents and the role of edge states.

Findings

Temperature gradient induces magnon spin Nernst effect.

Developed a general linear response theory for magnon Hall responses.

Applied theory to honeycomb lattice antiferromagnet, highlighting edge state contributions.

Abstract

We predict that a temperature gradient can induce a magnon-mediated spin Hall response in an antiferromagnet with non-trivial magnon Berry curvature. We develop a linear response theory which gives a general condition for a Hall current to be well defined, even when the thermal Hall response is forbidden by symmetry. We apply our theory to a honeycomb lattice antiferromagnet and discuss a role of magnon edge states in a finite geometry.