PAIR POTENTIAL AND DENSITY OF STATES IN PROXIMITY-CONTACT SUPERCONDUCTING NORMAL-METAL DOUBLE-LAYERS

The self-consistent pair potential and the density of states in a prox imity-contact superconducting-normal (S-N) finite double layer are dis cussed in the clean limit. The finite reflection coefficient R at the interface is explicitly taken into account. It is shown that the depre ssion of the pair potential near the S-N interface is significant even when the layer width is as small as the coherence length. We assume t hat there is no pairing interaction in the N side, and as a result the re is no pair potential. It is found, however, that the N-side density of states has an effective energy gap. In the S side, the density of states in the energy range below the pair potential is finite and has a remarkable structure in contrast to the bulk superconductor. The nuc lear spin-lattice relaxation rate T1(-1) is also calculated. The enhan cement of T1(-1) just below the transition temperature is found on bot h sides, which qualitatively agrees with experiments.