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 π orbitals. We also reveal that interfacial oxygen defects play an important role in determining the doping type of graphene near the interface. © 2019 American Physical Society.