Large sample-to-sample fluctuations of the nonequilibrium critical current through mesoscopic Josephson junctions

Abstract

We present a theory for the nonequilibrium current in a mesoscopic Josephson junction which is coupled to a normal electron reservoir, and apply it to a chaotic junction. Large sample-to-sample fluctuations of the critical current $I_{\rm c}$ are found, with ${rms} I_{\rm c} \simeq \sqrt{N}eΔ/\hbar$, when the voltage difference eV between the electron reservoir and the junction exceeds the superconducting gap $Δ$ and the number of modes N connecting the junction to the superconducting electrodes is large.