Electron Transport in Mesoscopic Disordered SNS Junctions

We have generalized the scattering-matrix theory of multiple Andreev reflections in mesoscopic Josephson junctions to the multi-mode case, and applied it to short superconductor/normal metal/superconductor junctions with diffusive electron transport. Both the dc and ac current-voltage characteristics are analyzed for a wide range of bias voltages \(V\). For voltages smaller than the supeconducting gap the dc differential conductance of the junction diverges as \(1/\sqrt{V}\).