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

TL;DR

This paper uses first-principles calculations to analyze electronic interactions at superconductor-graphene edge contacts, revealing how orbital hybridization and oxygen defects influence doping and superconducting behavior in Josephson junctions.

Contribution

It provides the first detailed first-principles insight into the electronic coupling mechanisms at superconductor-graphene edge contacts.

Findings

Orbital hybridization between molybdenum d orbitals and graphene π orbitals is crucial.

Interfacial oxygen defects significantly affect graphene doping near the contact.

Electronic coupling mechanisms influence the superconducting properties of the junction.

Abstract

Edge-contacted superconductor-graphene-superconductor Josephson junction have been utilized to realize topological superconductivity, which have shown superconducting signatures in the quantum Hall regime. We perform the 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 $\pi$ orbitals. We also reveal that interfacial oxygen defects play an important role in determining the doping type of graphene near the interface.