title: Competition for graphene: graphynes with direction-dependent Dirac cones.
abstract: The existence of Dirac cones in the band structure of two-dimensional materials accompanied by unprecedented electronic properties is considered to be a unique feature of graphene related to its hexagonal symmetry. Here, we present other two-dimensional carbon materials, graphynes, that also possess Dirac cones according to first-principles electronic structure calculations. One of these materials, 6,6,12-graphyne, does not have hexagonal symmetry and features two self-doped nonequivalent distorted Dirac cones suggesting electronic properties even more amazing than that of graphene.
authors.affiliation: Lehrstuhl für Theoretische Chemie and Interdisciplinary Center of Molecular Materials, Universität Erlangen-Nürnberg, Erlangen, Germany.
authors.forename: Daniel
authors.initials: D
authors.lastname: Malko
authors.forename: Christian
authors.initials: C
authors.lastname: Neiss
authors.forename: Francesc
authors.initials: F
authors.lastname: Viñes
authors.forename: Andreas
authors.initials: A
authors.lastname: Görling