Observation of supercurrent in PbIn-graphene-PbIn Josephson junction

Abstract

Superconductor-graphene-superconductor (SGS) junction provides a unique platform to study relativistic electrodynamics of Dirac fermions in graphene combined with proximity-induced superconductivity. We report the observation of the Josephson effect in proximity-coupled superconducting junctions of graphene in contact with ${\mathrm{Pb}}_{1\ensuremath{-}x}{\mathrm{In}}_{x}$ ($x=0.07$) electrodes for temperatures as high as $T$ $=$ 4.8 K, with a large value of ${I}_{c}{R}_{N}$ ($~$255 $\ensuremath{\mu}$ V). This demonstrates that ${\mathrm{Pb}}_{1\ensuremath{-}x}{\mathrm{In}}_{x}$ SGS junction would facilitate the development of the superconducting quantum information devices and superconductor-enhanced phase-coherent transport of graphene.