The quantum Hall phase transition at ν<sub>tot</sub> =1 in graphene double layers

ORAL

Abstract

We investigated the quantum Hall effect in graphene double layers which consist of two stacked graphene monolayers that are slightly rotated with respect to one another. We observe unexpected signatures of interlayer coherence resulting in odd-integer quantum Hall states (QHSs) at a balanced density between the layers (e.g νtot =1 = 1/2 + 1/2). We attribute the emergence of these QHSs to spontaneous layer coherence driven by interlayer Coulomb interactions, which are tunable using the magnetic field and the layer carrier densities. At fixed field a phase transition from the layer coherent state to the layer incoherent state is induced upon increasing density. This phase transition weakens and finally vanishes with increasing magnetic field.

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Presenters

  • Youngwook Kim

    • Max Planck Insitute for Solid State Research

Authors

  • Youngwook Kim

    • Max Planck Insitute for Solid State Research

  • Kenji Watanabe

    • National Institute for Materials Science
    • NIMS
    • National Institute for Material Science
    • Advanced Materials Laboratory, National Institute for Materials Science
    • National Institute of Materials Science
    • Research Center for Functional Materials, National Institute for Materials Science
    • National Institute for Materials Science (NIMS
    • Advanced Materials Laboratory, NIMS
    • National Institute for Materials Science, Advanced Materials Laboratory
    • National Institue for Materials Science
    • National Institute of Material Science
    • National Institute for Matericals Science
    • Advanced Materials Laboratory
    • National Institute for Materials Science, 1-1 Namiki
    • Advanced materials laboratory, National institute for Materials Science
    • NIMS-Japan

  • Takashi Taniguchi

    • National Institute for Materials Science
    • NIMS
    • National Institute for Material Science
    • Advanced Materials Laboratory, National Institute for Materials Science
    • National Institute of Materials Science
    • Research Center for Functional Materials, National Institute for Materials Science
    • National Institute for Materials Science (NIMS
    • Advanced Materials Laboratory, NIMS
    • National Institute for Materials Science, Advanced Materials Laboratory
    • National Institue for Materials Science
    • National Institute of Material Science
    • National Institute for Matericals Science
    • Advanced Materials Laboratory
    • National Institute for Materials Science, 1-1 Namiki
    • NIMS-Japan

  • Jurgen Smet

    • Max Planck Institute for Solid State Research
    • Max Planck Insitute for Solid State Research