Temperature dependence of the interface spin Seebeck effect

TL;DR

This study investigates how the interface spin Seebeck effect varies with temperature using optical pump-THz emission in YIG|Pt, revealing a continuous increase at lower temperatures and insights into magnon spectrum correlations.

Contribution

It provides the first detailed temperature-dependent analysis of the interface spin Seebeck effect using optical methods, highlighting the role of magnon bands.

Findings

Spin Seebeck effect increases as temperature decreases.

Temperature dependence of spin-mixing conductance is characterized.

Correlation between magnon spectrum features and spin Seebeck effect observed.

Abstract

We performed temperature-dependent optical pump - THz emission measurements in Y3Fe5O12 (YIG)|Pt from 5 K to room temperature in the presence of an externally applied magnetic field. We study the temperature dependence of the spin Seebeck effect and observe a continuous increase as temperature is decreased, opposite to what is observed in electrical measurements where the spin Seebeck effect is suppressed as 0K is approached. By quantitatively analysing the different contributions we isolate the temperature dependence of the spin-mixing conductance and observe features that are correlated to the bands of magnon spectrum in YIG.