title: Two-dimensional silicon monolayers generated on c-BN(111) substrate.
abstract: Silicene, a buckled two-dimensional honeycomb structure of silicon, has been experimentally synthesized on very few substrates. Furthermore, synthesizing silicene with a Dirac point is another hot research area. However, only silicene grown on Ag(111) has been reported to have a Dirac point, which has lowered the expectations of researchers. Here, three Si monolayer structures, a Si chain-type structure, a two-dimensional hexagonal close packed compound structure, and a two-dimensional hexagonal close packed structure, are generated on a c-BN(111) substrate using a particle-swarm optimization algorithm implemented in CALYPSO code. Band structure calculations show that all three structures exhibit a metallic nature. In particular, due to the absolutely flat conformation of the latter two structures, a linear dispersion exists near the Fermi energy level, indicating that charge carriers can transport like massless Dirac fermions. Our results open an alternative way of searching for other two-dimensional silicon monolayers with Dirac points.
authors.affiliation: State Key Laboratory of Superhard Materials, Jilin University, Changchun, 130012, China. mym@jlu.edu.cn.
authors.forename: Haiping
authors.initials: H
authors.lastname: Wu
authors.forename: Yan
authors.initials: Y
authors.lastname: Qian
authors.forename: Shaohua
authors.initials: S
authors.lastname: Lu
authors.forename: Erjun
authors.initials: E
authors.lastname: Kan
authors.forename: Ruifeng
authors.initials: R
authors.lastname: Lu
authors.forename: Kaiming
authors.initials: K
authors.lastname: Deng
authors.forename: Hui
authors.initials: H
authors.lastname: Wang
authors.forename: Yanming
authors.initials: Y
authors.lastname: Ma