Low-temperature proximity effect in clean metals

Abstract

Theories of proximity effect in layered superconductor-normal metal structures usually deal with a hypothetic normal metal with no interaction between electrons and with finite temperatures often close to the superconductor critical temperature. We present an asymptotic solution of the Gor'kov equations in the opposite low-temperature limit for a clean normal metal with a repulsive interaction between electrons. The order parameter in the metal exhibits a power-law decay, Delta(x) is proportional to 1/x, as a function of the distance from the SN boundary, x, with a proximity length strongly depending on the repulsive interaction.