Non-Reciprocal Transport of Thermally-Generated Magnons

TL;DR

This paper investigates the non-reciprocal transport of thermally-generated magnons in a YIG/Py system, revealing how magnon flow depends on magnetization orientation and temperature gradients, consistent with dipolar interaction models.

Contribution

It demonstrates the non-reciprocal behavior of thermally-generated magnons influenced by magnetization direction and dipolar interactions, providing experimental validation of theoretical symmetry predictions.

Findings

Magnon transport depends on the relative orientation of temperature gradient and magnetization.

Transport symmetries match those predicted by dipolar interaction models.

Directional magnon generation aligns with chiral spin Seebeck effect expectations.

Abstract

We demonstrate the non-reciprocity of electrically and thermally-generated incoherent magnon transport using the magnetization direction of a Py wire placed on top of an ultrathin YIG film. We show that the transport properties of thermally-generated magnons under a Py wire depends on the relative orientation between the temperature gradient and the Py-magnetization direction. The symmetries of this non-reciprocal magnon transport match with those predicted by the remote dipolar interaction between YIG and Py magnons, controlled by the chirality of the YIG magnon dipolar stray fields. We also show that the directional magnon generation by the spin Seebeck effect from the Py wire displays the symmetries expected from the chiral spin Seebeck effect.