Quantum interference hybrid spin-current injector

We propose a quantum interference spin-injector nanodevice consisting of a superconductor-normal metal hybrid loop connected to a superconductor-ferromagnet bilayer via a tunneling junction. We show that for certain values of the applied voltage bias across the tunnel barrier and the magnetic flux through the loop the spin-current can be fully polarized. Moreover, by tuning the magnetic flux one can switch the sign of the spin polarization. This operation can be performed at frequencies within the tens of GHz range. We explore the nanodevice in a wide range of parameters, establish the optimum conditions for its experimental realization and discuss its possible applications.