• 文献标题:   Broken symmetry nu=0 quantum Hall states in bilayer graphene: Landau level mixing and dynamical screening
  • 文献类型:   Article
  • 作  者:   GORBAR EV, GUSYNIN VP, MIRANSKY VA, SHOVKOVY IA
  • 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:   Taras Shevchenko Natl Kiev Univ
  • 被引频次:   29
  • DOI:   10.1103/PhysRevB.85.235460
  • 出版年:   2012

▎ 摘  要

For bilayer graphene in a magnetic field at the neutral point, we derive and solve a full set of gap equations including all Landau levels and taking into account the dynamically screened Coulomb interaction. There are two types of the solutions for the filling factor nu = 0: (i) a spin-polarized type solution, which is the ground state at small values of perpendicular electric field E-perpendicular to, and (ii) a layer-polarized solution, which is the ground state at large values of E-perpendicular to. The critical value of E. that determines the transition point is a linear function of the magnetic field, i.e., E-perpendicular to,E-cr = E-perpendicular to(off) + aB, where E-perpendicular to(off). is the offset electric field and a is the slope. The offset electric field and energy gaps substantially increase with the inclusion of dynamical screening compared to the case of static screening. The obtained values for the offset and the energy gaps are comparable with experimental ones. The interaction with dynamical screening can be strong enough for reordering the levels in the quasiparticle spectrum (the n = 2 Landau level sinks below the n = 0 and n = 1 ones).