Phonon-induced superconductivity at high temperatures in electrical graphene superlattices

Abstract

We discuss the BCS theory for electrons in graphene with a superimposed electrical unidirectional superlattice (SL) potential. New Dirac points emerge together with van Hove singularities (VHSs) linking them. We obtain a superconducting transition temperature Tc for chemical potentials close to the VHSs assuming that acoustic phonon coupling should be the dominant mechanism. Pairing of two onsite electrons with one electron close to the K and the other close to the −K point is the most stable pair formation. The resulting order parameter is almost constant over the entire SL.