Symmetry breaking in molecular artificial graphene

Research output: Contribution to journalArticle

Researchers

  • Linghao Yan

  • Muqing Hua
  • Qiushi Zhang
  • Tsz Ue Ngai
  • Zesheng Guo
  • Tsz Chun Wu
  • Tong Wang
  • Nian Lin

Research units

  • Hong Kong University of Science and Technology

Abstract

Symmetry breaking in graphene has profound impacts on its physical properties. Here we emulate symmetry breaking in artificial graphene systems by assembling coronene molecules on a Cu(111) surface. We apply two strategies: (1) differentiating the on-site energy of two sublattices of a honeycomb lattice and (2) uniaxially compressing a honeycomb lattice. The first one breaks the inversion symmetry while the second one merges the Dirac cones. The scanning tunneling spectroscopy shows that in both cases the local density of states undergo characteristic changes. Muffin-tin simulations reveal that the observed changes are associated with a band gap opened at the Dirac point. Furthermore, we propose that using larger molecules or molecules strongly scattering the surface state electrons can induce an indirect gap.

Details

Original languageEnglish
Article number083005
JournalNew Journal of Physics
Volume21
Issue number8
Publication statusPublished - 5 Aug 2019
MoE publication typeA1 Journal article-refereed

    Research areas

  • Artificial graphene, Gap opening, Molecular designer, Scanning tunneling spectroscopy

ID: 38325829