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.