Modulation of Spin Seebeck Effect by Hydrogenation

TL;DR

This study shows that hydrogenation significantly reduces the spin Seebeck effect in Pd/YIG bilayers, with effects reversible over days, indicating hydrogen's influence on spin current modulation.

Contribution

It is the first demonstration of modulating the spin Seebeck effect via hydrogenation in Pd/YIG bilayers, revealing a new method for controlling spin caloritronic phenomena.

Findings

Hydrogenation decreases SSE voltage by over 50%.

Hydrogen exposure reduces spin Hall magnetoresistance.

The SSE modulation is reversible but slow due to hydrogen desorption.

Abstract

We demonstrate the modulation of spin Seebeck effect (SSE) by hydrogenation in Pd/YIG bilayers. In the presence of 3% hydrogen gas, SSE voltage decreases by more than 50% from the magnitude observed in pure Ar gas. The modulation of the SSE voltage is reversible, but the recovery of the SSE voltage to the prehydrogenation value takes a few days because of a long time constant of hydrogen desorption. We also demonstrate that the spin Hall magnetoresistance of the identical sample reduces significantly with hydrogen exposure, supporting that the observed modulation of spin current signals originates from hydrogenation of Pd/YIG.