Local Charge and Spin Currents in Magnetothermal Landscapes

A scannable laser beam is used to generate local thermal gradients in metallic (${\mathrm{Co}}_2\mathrm{FeAl}$) or insulating (${\mathrm{Y}}_3{\mathrm{Fe}}_5{\mathrm{O}}_{12}$) 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 ${\mathrm{Co}}_2\mathrm{FeAl}$ 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 ${\mathrm{Y}}_3{\mathrm{Fe}}_5{\mathrm{O}}_{12}$. Our findings establish local thermal spin and charge current generation as well as spin caloritronic domain imaging.