Generation of pure superconducting spin current in magnetic heterostructures via nonlocally induced magnetism due to Landau Fermi liquid effects

Abstract

The authors propose a novel mechanism for the creation of superconducting spin currents in a ferromagnet/superconductor/normal-metal heterostructure via a non-locally induced exchange field in the normal layer, which exhibits Landau Fermi liquid interactions. When the structure enters the superconducting state, spin-triplet superconducting correlations transfer spin across the superconductor and induce remotely a magnetization in the normal layer. The authors then show that in the presence of strong spin-orbit interaction in the normal-metal layer, the induced magnetization is rotated with respect to the magnetization in the ferromagnet. This magnetization misalignment leads to a spin torque on both magnetizations and causes a superconducting spin current to flow across the superconductor. These results open new avenues for designing devices for superconducting spintronics.