Hole doping MgB${}_2$ without chemical substitution

Abstract

Structures for realizing hole-doped MgB${}_2$ without appealing to chemical substitutions are proposed. These structures which consist of alternating MgB${}_2$ and graphene layers have small excess energy compared to bulk graphite and MgB${}_2$. Density functional theory based first-principles electronic structure calculations show significant charge transfer from the MgB${}_2$ layer to graphene, resulting in effectively hole-doped MgB${}_2$. Substantial enhancement in the density of states at the Fermi level of the proposed structure is predicted.