Conductance and Its Fluctuations of Mesoscopic Wires in Contact with a Superconductor

Abstract

The conductance and its fluctuations in mesoscopic NS (N is a normal metal and S is a superconductor) wires are studied numerically. It is shown that the conductance fluctuations in the NS wire is enhanced as compared with an ordinary normal metal wire (N wire) by about a factor two. For the conductance itself, an enhancement which has been expected is found to vanish when the length of the normal segment is longer than the mean free path.