First-principles study of metal-graphene edge contact for ballistic Josephson junction

Edge-contacted superconductor-graphene-superconductor Josephson junctions have been utilized to realize topological superconductivity, and have shown superconducting signatures in the quantum Hall regime. We perform first-principles calculations to interpret electronic couplings at the superconductor-graphene edge contacts by investigating various aspects in hybridization of molybdenum $d$ orbitals and graphene \ensuremath{\pi} orbitals. We also reveal that interfacial oxygen defects play an important role in determining the doping type of graphene near the interface.