Coherence effects in conventional layered superconductors

We present and apply a theory for the coherence effects in spatially inhomogeneous layered superconductors. The theory is based upon a comparison of de Gennes's self-consistent equation for the pair potential to that of alternative proximity-effect models, from which the generalized, space-dependent BCS probability amplitudes u's and v's are obtained. Recent microwave surface impedance data of Pambianchi et al. on Nb/Cu bilayers are successfully reproduced.