Oscillations of Andreev states in clean ferromagnetic films

We investigate the influence of the exchange field on the Andreev bound states in a ferromagnetic (F) film backed on one side by a superconductor (S). Our model accounts for diffusive reflection at the outer surface and possible backscattering at the FS-interface. Phase shifting of the Andreev level by the exchange field results in an oscillatory behaviour of the density of states of F as a function of the layer thickness. We show that our results agree quantitatively with recent experiments.