title: Two dimensional Dirac carbon allotropes from graphene.
abstract: Using a structural search method in combination with first-principles calculations, we found lots of low energy 2D carbon allotropes and examined all possible Dirac points around their Fermi levels. Three amazing 2D Dirac carbon allotropes have been discovered, named as S-graphene, D-graphene and E-graphene. By analyzing the topology correlations among S-, T, net W graphene and graphene, we found that a general rule is valuable for constructing 2D carbon allotropes that are keen to possess Dirac cones in their electronic structures. Based on this rule, we have successfully designed many new 2D carbon allotropes possessing Dirac cones. Their energy order can be well described by an Ising-like model, and some allotropes are energetically more stable than those recently reported. The related electronic structures of these Dirac allotropes are anisotropy distinguished from those of graphene. Moreover, the fact that D- and E-graphene present Dirac cones suggests that sp hybridization or sp(3) hybridization could not suppress the emerging of Dirac features. Our results demonstrate that the Dirac cone and carrier linear dispersion is a very common feature in 2D carbon allotropes and can exist beyond the limitations of fundamental structure features of graphene.
authors.affiliation: College of Materials Science and Engineering, Beijing University of Technology, Beijing 100124, China. wrz@bjut.edu.cn miaoms@gmail.com limin.liu@csrc.ac.cn mym@jlu.edu.cn.
authors.forename: Li-Chun
authors.initials: LC
authors.lastname: Xu
authors.forename: Ru-Zhi
authors.initials: RZ
authors.lastname: Wang
authors.forename: Mao-Sheng
authors.initials: MS
authors.lastname: Miao
authors.forename: Xiao-Lin
authors.initials: XL
authors.lastname: Wei
authors.forename: Yuan-Ping
authors.initials: YP
authors.lastname: Chen
authors.forename: Hui
authors.initials: H
authors.lastname: Yan
authors.forename: Woon-Ming
authors.initials: WM
authors.lastname: Lau
authors.forename: Li-Min
authors.initials: LM
authors.lastname: Liu
authors.forename: Yan-Ming
authors.initials: YM
authors.lastname: Ma