Broken symmetry ν=0 quantum Hall states in bilayer graphene: Landau level mixing and dynamical screening

E. V. Gorbar, V. P. Gusynin, V. A. Miransky, Igor Shovkovy

    Research output: Contribution to journalArticlepeer-review

    36 Scopus citations

    Abstract

    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 ν=0: (i) a spin-polarized type solution, which is the ground state at small values of perpendicular electric field E , and (ii) a layer-polarized solution, which is the ground state at large values of E . The critical value of E that determines the transition point is a linear function of the magnetic field, i.e., E ⊥,cr=E⊥off+aB, where E⊥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).

    Original languageEnglish (US)
    Article number235460
    JournalPhysical Review B - Condensed Matter and Materials Physics
    Volume85
    Issue number23
    DOIs
    StatePublished - Jun 28 2012

    ASJC Scopus subject areas

    • Electronic, Optical and Magnetic Materials
    • Condensed Matter Physics

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