• 文献标题:   Coexisting Honeycomb and Kagome Characteristics in the Electronic Band Structure of Molecular Graphene
  • 文献类型:   Article
  • 作  者:   PAAVILAINEN S, ROPO M, NIEMINEN J, AKOLA J, RASANEN E
  • 作者关键词:   molecular graphene, density functional theory, tight binding, kekule, kagome
  • 出版物名称:   NANO LETTERS
  • ISSN:   1530-6984 EI 1530-6992
  • 通讯作者地址:   Tampere Univ Technol
  • 被引频次:   16
  • DOI:   10.1021/acs.nanolett.6b00397
  • 出版年:   2016

▎ 摘  要

We uncover the electronic structure of molecular graphene produced by adsorbed CO molecules on a copper (111) surface by means of first-principles calculations. Our results show that the band structure is fundamentally different from that of conventional graphene, and the unique features of the electronic states arise from coexisting honeycomb and Kagome symmetries. Furthermore, the Dirac cone does not appear at the K-point but at the G-point in the reciprocal space and is accompanied by a third, almost flat band. Calculations of the surface structure with Kekule distortion show a gap opening at the Dirac point in agreement with experiments. Simple tight-binding models are used to support the first-principles results and to explain the physical characteristics behind the electronic band structures.