Critical temperature of a proximity junction using Eliashberg theory

We present calculations for the critical temperature T/sub c/ of a proximity junction using the McMillan tunneling model but treating the metals on either sides within Eliashberg theory formulated on the imaginary axis. In addition we derive formulas for, and evaluate numerically, the functional derivative of T/sub c/ with respect to the electron-phonon spectral density of either side of the junction