Theoretical Investigation of Two-Dimensional Superconductivity in Intercalated Graphene Layers

Abstract

First-principles calculations of the electronic structure and vibrational modes, in a system of graphene bilayers and trilayers intercalated with alkaline earth atoms, are presented. It is found that, in similarity to the case of superconducting graphite intercalation compounds, the Fermi level is crossed by an s-band derived from the intercalant states, as well as graphitic π-bands. The electron-phonon coupling parameter λ is found to be 0.60 and 0.80, respectively, in calcium intercalated graphene bilayers and trilayers. In superconducting CaC6 graphite intercalation compound, the calculated value for λ is 0.83. It is concluded that two-dimensional superconductivity is possible in a system of a few graphene layers intercalated with calcium