Temperature profile of nanospintronic device analyzed by spin-dependent Seebeck effect

The heat transport in a laterally configured nano-spintronic device, including a magnetic multi-layered nanowire has been investigated by detecting the second harmonic voltages. We show that the magnetic-field dependence of the second harmonic voltage in the multi-layered wire shows a clear spin-valve-like effect with the magnitude larger than the electrical spin valve effect. The second harmonic signal with its probe configuration dependence is found to be quantitatively explained by the spin-dependent Seebeck effect with a significant heat flow from the substrate. This demonstration paves the way for the precise analysis of the heat flow in nano-structured electronic devices.