Propagation length of antiferromagnetic magnons governed by domain configurations

TL;DR

This study demonstrates micrometer-scale propagation of antiferromagnetic spin-waves in hematite thin films, showing that domain structures and domain walls significantly influence spin-wave attenuation, with potential for ultra-fast spintronic devices.

Contribution

It reveals how domain configurations affect spin-wave propagation length in antiferromagnetic thin films and demonstrates control over spin transport through domain engineering.

Findings

Efficient spin-wave propagation over micrometers in hematite thin films.

Domain walls cause increased spin-wave scattering and attenuation.

Tailoring domain structures enables zero-field spin-transport across micrometers.

Abstract

The compensated magnetic order and characteristic, terahertz frequencies of antiferromagnetic materials makes them promising candidates to develop a new class of robust, ultra-fast spintronic devices. The manipulation of antiferromagnetic spin-waves in thin films is anticipated to lead to new exotic phenomena such as spin-superfluidity, requiring an efficient propagation of spin-waves in thin films. However, the reported decay length in thin films has so far been limited to a few nanometers. In this work, we achieve efficient spin-wave propagation, over micrometer distances, in thin films of the insulating antiferromagnet hematite with large magnetic domains whilst evidencing much shorter attenuation lengths in multidomain thin films. Through transport and magnetic imaging, we conclude on the role of the magnetic domain structure and spin-wave scattering at domain walls to govern the transport. We manipulate the spin transport by tailoring the domain configuration through field cycle training. For the appropriate crystalline orientation, zero-field spin-transport is achieved across micrometers, as required for device integration.