Control of nonlocal magnon spin transport via magnon drift currents

TL;DR

This paper demonstrates the generation and control of magnon drift currents in magnetic insulators, revealing how interfacial interactions influence spin transport and extending theoretical models to include drift effects.

Contribution

It introduces a method to generate and control magnon drift currents via interfacial Dzyaloshinskii-Moriya interaction and generalizes magnonic spin transport theory to include drift velocity.

Findings

Magnon drift currents can be electrically generated and controlled.

Magnon drift modifies the propagation length by up to ±6%.

Theoretical model including drift velocity aligns with experimental results.

Abstract

Spin transport via magnon diffusion in magnetic insulators is important for a broad range of spin-based phenomena and devices. However, the absence of the magnon equivalent of an electric force is a bottleneck. In this work, we demonstrate the controlled generation of magnon drift currents in yttrium iron garnet/platinum heterostructures. By performing electrical injection and detection of incoherent magnons, we find magnon drift currents that stem from the interfacial Dzyaloshinskii-Moriya interaction. We can further control the magnon drift by the orientation of the magnetic field. The drift current changes the magnon propagation length by up to $\pm$ 6 % relative to diffusion. We generalize the magnonic spin transport theory to include a finite drift velocity resulting from any inversion asymmetric interaction, and obtain results consistent with our experiments.