title: Observation of Dirac cone warping and chirality effects in silicene.
abstract: We performed low temperature scanning tunneling microscopy (STM) and spectroscopy (STS) studies on the electronic properties of (√3 × √3)R30° phase of silicene on Ag(111) surface. We found the existence of Dirac Fermion chirality through the observation of -1.5 and -1.0 power law decay of quasiparticle interference (QPI) patterns. Moreover, in contrast to the trigonal warping of Dirac cone in graphene, we found that the Dirac cone of silicene is hexagonally warped, which is further confirmed by density functional calculations and explained by the unique superstructure of silicene. Our results demonstrate that the (√3 × √3)R30° phase is an ideal system to investigate the unique Dirac Fermion properties of silicene.
authors.affiliation: Institute of Physics, Chinese Academy of Sciences , Beijing 100190, China.
authors.forename: Baojie
authors.initials: B
authors.lastname: Feng
authors.forename: Hui
authors.initials: H
authors.lastname: Li
authors.forename: Cheng-Cheng
authors.initials: CC
authors.lastname: Liu
authors.forename: Ting-Na
authors.initials: TN
authors.lastname: Shao
authors.forename: Peng
authors.initials: P
authors.lastname: Cheng
authors.forename: Yugui
authors.initials: Y
authors.lastname: Yao
authors.forename: Sheng
authors.initials: S
authors.lastname: Meng
authors.forename: Lan
authors.initials: L
authors.lastname: Chen
authors.forename: Kehui
authors.initials: K
authors.lastname: Wu