Superconductivity from electronic interactions and spin-orbit enhancement in bilayer and trilayer graphene

Abstract

What drives superconductivity in non-moir\'e graphene? Here, an electron-electron mechanism is applied to the continuum framework of Bernal bilayer and rhombohedral trilayer graphene. Within a Kohn-Luttinger-like approach, the internal screening of the long-range Coulomb potential leads to an effective attraction between carriers, enabling the formation of Cooper pairs. The calculations provide a filling-dependent critical temperature that is remarkably enhanced due to Ising spin-orbit coupling, and determine the spin-triplet valley-singlet symmetry of the superconducting order parameter, in line with recent experimental advances.