Local charge and spin currents in magnetothermal landscapes

TL;DR

This paper demonstrates local thermal generation of charge and spin currents in ferromagnetic thin films using laser-induced thermal gradients, advancing spin caloritronics and domain imaging techniques.

Contribution

It introduces a method to generate and detect local charge and spin currents via the anomalous Nernst and spin Seebeck effects using laser heating.

Findings

Local thermal charge currents detected via anomalous Nernst effect.

Local spin currents observed through inverse spin Hall effect.

Method enables spin caloritronic domain imaging.

Abstract

A scannable laser beam is used to generate local thermal gradients in metallic (Co2FeAl) or insulating (Y3Fe5O12) ferromagnetic thin films. We study the resulting local charge and spin currents that arise due to the anomalous Nernst effect (ANE) and the spin Seebeck effect (SSE), respectively. In the local ANE experiments, we detect the voltage in the Co2FeAl thin film plane as a function of the laser spot position and external magnetic field magnitude and orientation. The local SSE effect is detected in a similar fashion by exploiting the inverse spin Hall effect in a Pt layer deposited on top of the Y3Fe5O12. Our findings establish local thermal spin and charge current generation as well as spin caloritronic domain imaging.