• 文献标题:   Band gaps in graphene via periodic electrostatic gating
  • 文献类型:   Article
  • 作  者:   PEDERSEN JG, PEDERSEN TG
  • 作者关键词:  
  • 出版物名称:   PHYSICAL REVIEW B
  • ISSN:   2469-9950 EI 2469-9969
  • 通讯作者地址:   Aalborg Univ
  • 被引频次:   19
  • DOI:   10.1103/PhysRevB.85.235432
  • 出版年:   2012

▎ 摘  要

Much attention has been focused on ways of rendering graphene semiconducting. We study periodically gated graphene in a tight-binding model and find that, contrary to predictions based on the Dirac equation, it is possible to open a band gap at the Fermi level using electrostatic gating of graphene. However, comparing to other methods of periodically modulating graphene, namely, perforated graphene structures, we find that the resulting band gap is significantly smaller. We discuss the intricate dependence of the band gap on the magnitude of the gate potential as well as the exact geometry of the edge of the gate region. The role of the overlap of the eigenstates with the gate region is elucidated. Considering more realistic gate potentials, we find that introducing smoothing in the potential distribution, even over a range of little more than a single carbon atom, reduces the attainable band gap significantly. This represents a serious challenge to achieving gapped graphene via periodic gating.