Magnon equilibrium spin current in collinear antiferromagnets

TL;DR

This paper predicts that Dzyaloshinskii-Moriya interaction can generate observable magnon equilibrium spin currents in collinear antiferromagnets, akin to supercurrents, and proposes an experimental verification method.

Contribution

It introduces the concept of magnon equilibrium spin currents induced by Dzyaloshinskii-Moriya interaction in collinear antiferromagnets, a novel theoretical prediction.

Findings

Magnon equilibrium spin current can be induced by Dzyaloshinskii-Moriya interaction.

The effect is analogous to supercurrents in superconductors.

An experimental setup using magnon interference in a ring is proposed.

Abstract

We theoretically predict that the Dzyaloshinskii-Moriya interaction can induce a magnon equilibrium spin current in collinear antiferromagnets. Such a current, being a response to the effective magnon vector potential, can be considered the magnon analog of the supercurrent in superconductors. The large amplitude of the predicted effect may compensate for the smallness of the Dzyaloshinskii-Moriya interaction, making the equilibrium spin currents experimentally observable. We suggest that an external electric field can play the role of an effective flux that magnons interact with, and we propose an experiment based on the interference of magnons in a ring geometry to verify the concept.