QUROPE Quantum Information Processing and Communication in Europe

We report a new way to strongly couple graphene to a superconductor. The graphene monolayer has been grown directly on top of a superconducting Re(0001) thin film and characterized by scanning tunneling microscopy and spectroscopy. We observed a moir\'{e} pattern due to the mismatch between Re and graphene lattice parameters, that we have simulated with \textit{ab initio} calculations. The density of states around the Fermi energy appears to be position dependent on this moir\'{e} pattern. Tunneling spectroscopy performed at 50 mK shows that the superconducting behavior of graphene on Re is well described by the Bardeen-Cooper-Schrieffer theory and stands for a very good interface between the graphene and its metallic substrate.