• 文献标题:   Intra-Landau-level magnetoexcitons and the transition between quantum Hall states in undoped bilayer graphene
  • 文献类型:   Article
  • 作  者:   TOKE C, FAL KO VI
  • 作者关键词:  
  • 出版物名称:   PHYSICAL REVIEW B
  • ISSN:   1098-0121
  • 通讯作者地址:   Univ Pecs
  • 被引频次:   23
  • DOI:   10.1103/PhysRevB.83.115455
  • 出版年:   2011

▎ 摘  要

We study the collective modes of the quantum Hall states in undoped bilayer graphene in a strong perpendicular magnetic and electric field. Both for the well-known ferromagnetic state that is relevant for small electric field E(perpendicular to) and the analogous layer polarized one suitable for large E(perpendicular to), the low-energy physics is dominated by magnetoexcitons with zero angular momentum that are even combinations of excitons that conserve Landau orbitals. We identify a long-wavelength instability in both states, and argue that there is an intermediate range of the electric field E(c)((1)) < E(perpendicular to) < E(c)((s)) where a gapless phase interpolates between the incompressible quantum Hall states. The experimental relevance of this crossover via a gapless state is discussed.