Theory of the electronic structure of alternating MgB2 and graphene layered structures

Structures for realizing hole-doped MgB2 without appealing to chemical substitutions are proposed. These structures that consist of alternating MgB2 and graphene layers have small excess energy compared to bulk graphite and MgB2. Density functional theory based first-principles electronic structure calculations show significant charge transfer from the MgB2 layer to graphene, resulting in effectively hole-doped MgB2 and electron-doped graphene. Substantial enhancement in the density of states at the Fermi level and significant in-plane lattice expansion of the proposed structures are predicted. These structures combines three important factors, namely, hole doping, high density of states at the Fermi level, and in-plane lattice expansion, that are favorable for a strong electron-phonon coupling.