Observation of Magnetic State Dependent Thermoelectricity in Superconducting Spin Valves
César González‐Ruano, Diego Caso, Jabir Ali Ouassou, C. Tiuşan, Yuan Lü, Jacob Linder, F. G. Aliev
Abstract
Superconductor-ferromagnet tunnel junctions demonstrate giant thermoelectric effects that are being exploited to engineer ultrasensitive terahertz radiation detectors. Here, we experimentally observe the recently predicted complete magnetic control over thermoelectric effects in a superconducting spin valve, including the dependence of its sign on the magnetic state of the spin valve. The description of the experimental results is improved by the introduction of an interfacial domain wall in the spin filter layer interfacing the superconductor. Surprisingly, the application of high in-plane magnetic fields induces a double sign inversion of the thermoelectric effect, which exhibits large values even at applied fields twice the superconducting critical field.