Theory of drift-enabled control in nonlocal magnon transport

TL;DR

This paper explores how drift currents can control magnon transport in magnetic insulators, identifying temperature gradients as especially effective for tuning magnon propagation length.

Contribution

It introduces a phenomenological framework for understanding magnon drift and highlights temperature gradients as a key mechanism for controlling magnon transport.

Findings

Temperature gradient effectively induces magnon drift.

Magnetic field gradient influences magnon propagation.

Asymmetric dispersion contributes to magnon drift.

Abstract

Electrically injected and detected nonlocal magnon transport has emerged as a versatile method for transporting spin as well as probing the spin excitations in a magnetic insulator. We examine the role of drift currents in this phenomenon as a method for controlling the magnon propagation length. Formulating a phenomenological description, we identify the essential requirements for existence of magnon drift. Guided by this insight, we examine magnetic field gradient, asymmetric contribution to dispersion, and temperature gradient as three representative mechanisms underlying a finite magnon drift velocity, finding temperature gradient to be particularly effective.