Competition between zero bias anomaly and proximity effect in disordered systems

We investigate the suppression of the proximity effect in mesoscopic normal metal/superconductor systems induced by Coulomb interaction. We identify and elucidate the mechanism by which disorder leads to an amplification of this effect. In particular, for strong enough disorder, the proximity effect is shown to vanish. An expression for the tunneling density of states is obtained, and experimental applications are discussed.