Phonon driven spin distribution due to the spin-Seebeck effect

TL;DR

This study demonstrates that phonons drive the spin redistribution in GaMnAs via the spin-Seebeck effect, with the effect's amplitude correlating with thermal conductivity and phonon-drag thermoelectric contributions.

Contribution

It provides experimental evidence and a phenomenological model showing phonon-driven spin distribution in GaMnAs, expanding understanding of spin-phonon interactions.

Findings

Spin-Seebeck effect amplitude scales with substrate thermal conductivity

Phonon-drag significantly influences thermoelectric power in GaMnAs

Phonon-magnon drag explains the spatial and temperature dependence of spin distribution

Abstract

Here we report on measurements of the spin-Seebeck effect of GaMnAs over an extended temperature range alongside the thermal conductivity, specific heat, magnetization, and thermoelectric power. The amplitude of the spin-Seebeck effect in GaMnAs scales with the thermal conductivity of the GaAs substrate and the phonon-drag contribution to the thermoelectric power of the GaMnAs, demonstrating that phonons drive the spin redistribution. A phenomenological model involving phonon-magnon drag explains the spatial and temperature dependence of the measured spin distribution.