DENSITY-OF-STATES OF A LAYERED S/N D-WAVE SUPERCONDUCTOR

We calculate the density of states of a layered superconductor in which there are two layers per unit cell. One of the layers contains a d-wave pairing interaction while the other is a normal metal. The goal of this article is to understand how the d-wave behavior of the system is modified by the coupling between the layer types. This coupling takes the form of coherent, single-particle tunneling along the c axis. We find that there are two physically different limits of behavior, which depend on the relative locations of the Fermi surfaces of the two layer types. We also discuss the interference between the interlayer coupling and pairing interaction and we find that this interference leads to features in the density of states. © 1995 The American Physical Society.