Enhanced Josephson coupling in hybrid nanojunctions

We have fabricated NbN/Au nanogaps and bridged them with an Al superconductor using Ti as interlayer. The nanodevices show a critical current density at 300 mK high $3\ifmmode\times\else\texttimes\fi{}{10}^{6}\phantom{\rule{4pt}{0ex}}{\text{A/cm}}^{2}$, which is $30%$ higher than that of nanowires the same lateral dimensions NbN-based devices. response function external magnetic field clearly showed Fraunhofer-like behavior, indicating Josephson coupling between NbN electrodes through barrier. superconducting transport evolves into different regimes temperature. These findings demonstrate importance barriers in hybrid to achieve very great relevance circuits requiring integration density.