Superconducting Valve Exploiting Interplay between Spin-Orbit and Exchange Interactions

We theoretically investigated the proximity effect in SNSOF and SF’F structures consisting of a superconductor (S), a normal metal (NSO), and ferromagnetic (F’,F) thin films with spin–orbit interaction (SOI) in the NSO layer. We show that a normal layer with spin–orbit interaction effectively suppresses triplet correlations generated in a ferromagnetic layer. Due to this effect, the critical temperature of the superconducting layer in the SNSOF multilayer turns out to be higher than in a similar multilayer without spin–orbit interaction in the N layer. Moreover, in the presence of a mixed type of spin–orbit interaction involving the Rashba and Dresselhaus components, the SNSOF structure is a spin valve, whose critical temperature is determined by the direction of the magnetization vector in the F layer. We calculated the control characteristics of the SNSOF spin valve and compared them with those available in traditional SF’F devices with two ferromagnetic layers. We concluded that SNSOF structures with one controlled F layer provide solid advantages over the broadly considered SF’F spin valves, paving the way for high-performance storage components for superconducting electronics.