• 文献标题:   Finite-size effects and interactions in artificial graphene formed by repulsive scatterers
  • 文献类型:   Article
  • 作  者:   KYLANPAA I, AICHINGER M, JANECEK S, RASANEN E
  • 作者关键词:   artificial graphene, dirac point, densityfunctional theory, realspace method
  • 出版物名称:   JOURNAL OF PHYSICSCONDENSED MATTER
  • ISSN:   0953-8984 EI 1361-648X
  • 通讯作者地址:   Tampere Univ Technol
  • 被引频次:   3
  • DOI:   10.1088/0953-8984/27/42/425501
  • 出版年:   2015

▎ 摘  要

We carry out a numerical real-space study on electrons confined in a two-dimensional triangular lattice of repulsive scattering centres. The system represents a qualitative model of molecular graphene, where the electron gas is confined between the scattering molecules in a hexagonal configuration. Our main interest is, on one hand, in the comparability of a finite system (flake) and a fully periodic one, and, on the other hand, in the role of the Coulombic electron-electron interactions and the relative strength of the scattering centres. Our real-space study shows in detail how the density of states of the fully periodic system-containing the Dirac point-is gradually formed as the size of the flake is increased. Good qualitative agreement with the experimental density of states is obtained. Our study confirms the minor role of the electron-electron interactions with selected system parameters, and shows in detail that large scattering amplitudes are required to obtain a distinctive Dirac point in the density of states.