Lateral transport properties of thermally excited magnons in yttrium iron garnet films

TL;DR

This study investigates how thermally excited magnons move laterally in yttrium iron garnet films, revealing polarity reversals dependent on temperature and geometry, and proposes a two-channel transport model to explain these phenomena.

Contribution

It introduces a competing two-channel transport model for thermally excited magnons in YIG, advancing understanding of insulator magnon transport and aiding magnonics development.

Findings

Polarity reversals of spin signals depend on temperature, film thickness, and separation.

A two-channel transport model qualitatively explains the observed spin behavior.

The work provides a controllable magnon source for magnonic applications.

Abstract

Spin information carried by magnons is attractive for computing technology and the development of magnon-based computing circuits is of great interest. However, magnon transport in insulators has been challenging, different from the clear physical picture for spin transport in conductors. Here we investigate the lateral transport properties of thermally excited magnons in yttrium iron garnet (YIG), a model magnetic insulator. Polarity reversals of detected spins in non-local geometry devices have been experimentally observed and are strongly dependent on temperature, YIG film thickness, and injector-detector separation distance. A competing two-channel transport model for thermally excited magnons is proposed, which is qualitatively consistent with the spin signal behavior. In addition to the fundamental significance for thermal magnon transport, our work furthers the development of magnonics by creating an easily accessible magnon source with controllable transport