Magnon transport in $\mathrm{\mathbf{Y_3Fe_5O_{12}}}$/Pt nanostructures with reduced effective magnetization

TL;DR

This study demonstrates that reducing the effective magnetization in yttrium iron garnet thin films enhances magnon transport, with a sixfold increase in conductivity via damping compensation controlled by current and magnetic field.

Contribution

It reveals how reduced effective magnetization improves magnon conductivity and introduces a method to control it using current-induced damping compensation.

Findings

Magnon conductivity increases up to six times with damping compensation.

Threshold current for damping compensation depends linearly on magnetic field.

Reduced magnetization leads to nearly circular magnetization precession.

Abstract

For applications making use of magnonic spin currents damping effects, which decrease the spin conductivity, have to be minimized. We here investigate the magnon transport in an yttrium iron garnet thin film with strongly reduced effective magnetization. We show that in a three-terminal device the effective magnon conductivity can be increased by a factor of up to six by a current applied to a modulator electrode, which generates damping compensation above a threshold current. Moreover, we find a linear dependence of this threshold current on the applied magnetic field. We can explain this behavior by the reduced effective magnetization and the associated nearly circular magnetization precession.