GENERALIZED MCMILLAN TUNNELING MODEL OF THE SUPERCONDUCTING PROXIMITY EFFECT

We have extended the McMillan tunneling model (MTM) of the superconducting proximity effect to the case of strongly coupled normal-superconducting composites. The generalization has been carried out by treating the tunneling Hamiltonian to all orders of self-consistent perturbation theory. The electronic density of states, the real and imaginary parts of the order parameter, the energy gap, and the transition temperature Tc calculated in the generalized model are significantly different from the MTM results. Generally, the peak in NN (E) is broader, shifted, and damped. The energy gap is lower and the depression in Tc is softened. © 1979 Plenum Publishing Corporation.