Unusual spin-triplet superconductivity in monolayer graphene

Abstract

In this paper, we consider the phonons in monolayer graphene and we show the possibility for the spin-triplet superconducting excitations states by discretizing the single-particle excitations near Fermi wave vector. The monolayer graphene was supposed to be exposed under the influence of the external gate-potential and the local Coulomb interaction effects have been taken into account at each lattice site position in the monolayer. A sufficiently large temperature domain was found, where the superconducting order parameter is not vanishing. Corresponding to this, at the surprisingly high temperature limit, we obtain a narrow domain of the electron–phonon coupling parameter \(\lambda _\textrm{eff}\), emphasizing the superconducting state. We discuss the localizing role of Hubbard-U interaction and the effects external gate potential on the calculated physical parameters in the system. We explain the importance of the chemical potential in the formation of the superconducting state. We show the existence of a large superconducting band-gap in the system even in the case of the absence of the applied electric field potential.