Meservey-Tedrow effect in ferromagnet/superconductor/ferromagnet double tunnel junctions

Double tunneling junctions of ferromagnet-superconductor-ferromagnet electrodes (FSF) show a step in the conductance when a parallel magnetic field reverses the magnetization of one of the ferromagnetic electrodes. This change is generally attributed to the spin-valve effect or to pair breaking in the superconductor due to spin accumulation. In this paper it is shown that the Meservey-Tedrow effect causes a similar change in the conductance since the magnetic field changes the energy spectrum of the quasiparticles in the superconductor. A reversal of the bias reverses the sign in the conductance jump.