Simultaneous detection of the spin-Hall magnetoresistance and the spin-Seebeck effect in Platinum and Tantalum on Yttrium Iron Garnet

TL;DR

This paper demonstrates a method to simultaneously detect the spin-Hall magnetoresistance and the spin-Seebeck effect in Pt and Ta on YIG using current-induced heating and lock-in detection, revealing additional magnetic field effects.

Contribution

It introduces a novel measurement technique that separates SSE from SMR signals during current-induced heating, highlighting the presence of dynamic SMR signals at low magnetic fields.

Findings

Current-induced heating can directly observe SSE.

Lock-in detection separates SSE from SMR signals.

Additional 2nd order signals caused by Oersted fields are identified.

Abstract

The spin-Seebeck effect (SSE) in platinum (Pt) and tantalum (Ta) on yttrium iron garnet (YIG) has been investigated by both externally heating the sample (using an on-chip Pt heater on top of the device) as well as by current-induced heating. For SSE measurements, external heating is the most common method to obtain clear signals. Here we show that also by current-induced heating it is possible to directly observe the SSE, separate from the also present spin-Hall magnetoresistance (SMR) signal, by using a lock-in detection technique. Using this measurement technique, the presence of additional 2nd order signals at low applied magnetic fields and high heating currents is revealed. These signals are caused by current-induced magnetic fields (Oersted fields) generated by the used AC-current, resulting in dynamic SMR signals.