A new Dirac cone material: a graphene-like Be3C2 monolayer

Abstract

Two-dimensional (2D) materials with Dirac cones exhibit rich physics and many intriguing properties, but the search for new 2D Dirac materials is still a current hotspot. Using the global particle-swarm optimization method and density functional theory, we predict a new stable graphene-like 2D Dirac material: a Be₃C₂ monolayer with a hexagonal honeycomb structure. The Dirac point occurs exactly at the Fermi level and arises from the merging of the hybridized p_z bands of Be and C atoms. Most interestingly, this monolayer exhibits a high Fermi velocity in the same order of graphene. Moreover, the Dirac cone is very robust and retains even included spin–orbit coupling or external strain. These outstanding properties render the Be₃C₂ monolayer a promising 2D material for special electronics applications.