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

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 $I_{\mathrm{c}}$ are found, with rms $I_{\mathrm{c}}\simeq \sqrt{N}e\Delta /ħ,$ when the voltage difference $\mathrm{eV}$ between the electron reservoir and the junction exceeds the superconducting gap $\Delta$ and the number of modes N connecting the junction to the superconducting electrodes is large.