Josephson current in nanofabricated V/Cu/V mesoscopic junctions

We report the fabrication of planar V/Cu/V mesoscopic Josephson weak links of different size and the analysis of their low-temperature behavior. The shorter junctions exhibit critical currents of several tens of microamperes at 350 mK, while Josephson coupling persists up to similar to 2.7 K. Good agreement is obtained by comparing the measured switching currents to a model which holds in the diffusive regime. Our results demonstrate that V is an excellent candidate for the implementation of superconducting nanodevices operating at a few kelvins.