Oscillations of Andreev states in clean ferromagnetic films

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