# Spin conductance of YIG thin films driven from thermal to subthermal magnons regime by large spin-orbit torque

## TL;DR

This paper investigates how spin conductance in ultra-thin YIG films transitions from thermal to non-thermal magnon regimes under large spin-orbit torque, revealing new insights into magnon dynamics and field sensitivity.

## Contribution

It demonstrates the transition from thermal to non-equilibrium magnon transport in YIG films driven by large spin-orbit torque, supported by Brillouin Light Scattering spectroscopy.

## Key findings

- Thermal magnons dominate at low current
- Non-equilibrium magnons dominate at high current
- Longer decay length and field sensitivity observed in non-thermal regime

## Abstract

We report a study on spin conductance in ultra-thin films of Yttrium Iron Garnet (YIG), where spin transport is provided by propagating spin waves, that are generated and detected by direct and inverse spin Hall effects in two Pt wires deposited on top. While at low current the spin conductance is dominated by transport of thermal magnons, at high current, the spin conductance is dominated by low-damping non-equilibrium magnons thermalized near the spectral bottom by magnon-magnon interaction, with consequent a sensitivity to the applied magnetic field and a longer decay length. This picture is supported by microfocus Brillouin Light Scattering spectroscopy.