title: Dirac semimetal in three dimensions.
abstract: We show that the pseudorelativistic physics of graphene near the Fermi level can be extended to three dimensional (3D) materials. Unlike in phase transitions from inversion symmetric topological to normal insulators, we show that particular space groups also allow 3D Dirac points as symmetry protected degeneracies. We provide criteria necessary to identify these groups and, as an example, present ab initio calculations of β-cristobalite BiO(2) which exhibits three Dirac points at the Fermi level. We find that β-cristobalite BiO(2) is metastable, so it can be physically realized as a 3D analog to graphene.
authors.affiliation: The Makineni Theoretical Laboratories, Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6323, USA.
authors.forename: S M
authors.initials: SM
authors.lastname: Young
authors.forename: S
authors.initials: S
authors.lastname: Zaheer
authors.forename: J C Y
authors.initials: JC
authors.lastname: Teo
authors.forename: C L
authors.initials: CL
authors.lastname: Kane
authors.forename: E J
authors.initials: EJ
authors.lastname: Mele
authors.forename: A M
authors.initials: AM
authors.lastname: Rappe