Magnon Thermal Edelstein Effect Detected by Inverse Spin Hall Effect

TL;DR

This paper theoretically demonstrates the magnon thermal Edelstein effect in an antiferromagnet with DMI, showing how temperature gradients induce spin polarization detectable via inverse spin Hall voltage, with dependencies on material parameters.

Contribution

It introduces the concept of the magnon thermal Edelstein effect in antiferromagnets with DMI and analyzes its detection through inverse spin Hall effect.

Findings

Inverse spin Hall voltage depends monotonically on temperature and DMI.

The effect is non-monotonic with hard-axis anisotropy.

The effect is an even function of magnetic field along the Néel vector.

Abstract

In an easy-plane antiferromagnet with the Dzyaloshinskii-Moriya interaction (DMI), magnons are subject to an effective spin-momentum locking. An in-plane temperature gradient can generate interfacial accumulation of magnons with a specified polarization, realizing the magnon thermal Edelstein effect. We theoretically investigate the injection and detection of this thermally-driven spin polarization in an adjacent heavy metal with strong spin Hall effect. We find that the inverse spin Hall voltage depends monotonically on both temperature and the DMI but non-monotonically on the hard-axis anisotropy. Counterintuitively, the magnon thermal Edelstein effect is an even function of a magnetic field applied along the N\'eel vector.