Coherence effects in conventional layered superconductors

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