Disorder-Induced Suppression of Antiferromagnetic Magnon Transport in Cr2O3

TL;DR

This study investigates how structural spin disorder in Cr2O3 affects antiferromagnetic magnon transport, revealing that disorder can completely suppress magnon propagation in films thicker than 3 nm.

Contribution

It demonstrates the critical influence of point defect-induced disorder on magnon transport in antiferromagnetic Cr2O3 films, using systematic thickness variation and spin Seebeck measurements.

Findings

Magnon transport is suppressed in films >3 nm thick due to disorder.

Spin-flop transition field varies with defect density.

Disorder critically impacts antiferromagnetic magnon propagation.

Abstract

We explore the impact of spin disorder associated with structural defects on antiferromagnetic magnon transport by probing the spin-flop transition of Cr2O3 using spin Seebeck effect measurements. By fabricating homoepitaxial Cr2O3 films grown on smooth Cr2O3 crystals, we systematically vary the thickness of the films in which the presence of point defects modulates the spin-flop transition field. We find that magnon propagation through the film is entirely suppressed for film thickness greater than 3 nm, revealing the pivotal role of disorder in governing antiferromagnetic magnon transport.