High critical-current superconductor-InAs nanowire-superconductor junctions

We report on InAs nanowires coupled to superconducting leads with high critical current and widely tunable conductance. We implemented a double lift-off nanofabrication method to get very short nanowire devices with Ohmic contacts. We observe very high critical currents of up to 800\,nA in a wire with a diameter of 80\,nm. The current-voltage characteristics of longer and suspended nanowires display either Coulomb blockade or supercurrent depending on a local gate voltage, combining different regimes of transport in a single device. In addition, both the conductance and the critical current of the suspended devices increased step-wise as a function of the local gate voltage.