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. 
M. Zareyan (1 and 2), W. Belzig (1), and Yu.V. Nazarov (1) ((1) TU   Delft, Netherlands (2) IASBS Zanjan, Iran)