title: Identifying Dirac cones in carbon allotropes with square symmetry.
abstract: A theoretical study is conducted to search for Dirac cones in two-dimensional carbon allotropes with square symmetry. By enumerating the carbon atoms in a unit cell up to 12, an allotrope with octatomic rings is recognized to possess Dirac cones under a simple tight-binding approach. The obtained Dirac cones are accompanied by flat bands at the Fermi level, and the resulting massless Dirac-Weyl fermions are chiral particles with a pseudospin of S = 1, rather than the conventional S = 1∕2 of graphene. The spin-1 Dirac cones are also predicted to exist in hexagonal graphene antidot lattices.
authors: College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China.
authors: Jinying
authors: J
authors: Wang
authors: Huaqing
authors: H
authors: Huang
authors: Wenhui
authors: W
authors: Duan
authors: Zhirong
authors: Z
authors: Liu