• 文献标题:   Topological Invariants of Eigenvalue Intersections and Decrease of Wannier Functions in Graphene
  • 文献类型:   Article
  • 作  者:   MONACO D, PANATI G
  • 作者关键词:   wannier function, bloch bundle, conical intersection, eigenspace vorticity, pseudospin winding number, graphene
  • 出版物名称:   JOURNAL OF STATISTICAL PHYSICS
  • ISSN:   0022-4715 EI 1572-9613
  • 通讯作者地址:   Univ Roma La Sapienza
  • 被引频次:   6
  • DOI:   10.1007/s10955-014-0918-x
  • 出版年:   2014

▎ 摘  要

We investigate the asymptotic decrease of the Wannier functions for the valence and conduction band of graphene, both in the monolayer and the multilayer case. Since the decrease of the Wannier functions is characterised by the structure of the Bloch eigenspaces around the Dirac points, we introduce a geometric invariant of the family of eigenspaces, baptised eigenspace vorticity. We compare it with the pseudospin winding number. For every value of the eigenspace vorticity, we exhibit a canonical model for the local topology of the eigenspaces. With the help of these canonical models, we show that the single band Wannier function satisfies as , both in monolayer and bilayer graphene.