Concomitant enhancement of longitudinal spin Seebeck effect with thermal conductivity

TL;DR

This study demonstrates a correlated enhancement of the longitudinal spin Seebeck effect and thermal conductivity in YIG, revealing a strong link between magnon and phonon transport mechanisms in the system.

Contribution

It provides the first direct measurement showing simultaneous peaks of LSSE and thermal conductivity, indicating a strong magnon-phonon coupling in YIG.

Findings

LSSE signal peaks at the same temperature as thermal conductivity

Maximum LSSE coefficient exceeds 10 μV/K, surpassing previous reports

Strong correlation between magnon and phonon transport in LSSE

Abstract

We report a simultaneous measurement of a longitudinal spin Seebeck effect (LSSE) and thermal conductivity in a Pt/${\rm Y_{3}Fe_{5}O_{12}}$ (YIG)/Pt system in a temperature range from 10 to 300 K. By directly monitoring the temperature difference in the system, we excluded thermal artifacts in the LSSE measurements. It is found that both the LSSE signal and the thermal conductivity of YIG exhibit sharp peaks at the same temperature, differently from previous reports. The maximum LSSE coefficient is found to be $S{\rm_{LSSE}}>10\ \mu{\rm V/K}$, one-order-of magnitude greater than the previously reported values. The concomitant enhancement of the LSSE and thermal conductivity of YIG suggests the strong correlation between magnon and phonon transport in the LSSE.