Spin Pumping of an Easy-Plane Antiferromagnet Enhanced by Dzyaloshinskii-Moriya Interaction

TL;DR

This paper demonstrates dc spin pumping in a canted easy-plane antiferromagnet, {}-FeOa3, enhanced by Dzyaloshinskii-Moriya interaction, showing potential for ultrafast spintronic applications.

Contribution

It reveals the mechanism of spin pumping via acoustic resonant modes in antiferromagnets, a novel approach enabled by Dzyaloshinskii-Moriya interaction.

Findings

Spin pumping signals originate from resonance-induced spin injection.

Reversal of spin signal polarity confirms pure spin current nature.

Low-frequency acoustic modes can be harnessed for spintronic devices.

Abstract

Recently, antiferromagnets have received revived interest due to their significant potential for developing next-generation ultrafast magnetic storage. Here we report dc spin pumping by the acoustic resonant mode in a canted easy-plane antiferromagnet {\alpha}-Fe2O3 enabled by the Dzyaloshinskii-Moriya interaction. Systematic angle and frequency dependent measurements demonstrate that the observed spin pumping signals arise from resonance-induced spin injection and inverse spin Hall effect in {\alpha}-Fe2O3/metal heterostructures, mimicking the behavior of spin pumping in conventional ferromagnet/nonmagnet systems. The pure spin current nature is further corroborated by reversal of the polarity of spin pumping signals when the spin detector is switched from platinum to tungsten which has an opposite sign of the spin Hall angle. Our results highlight the potential opportunities offered by the low-frequency acoustic resonant mode in canted easy-plane antiferromagnets for developing next-generation, functional spintronic devices.