Topological phases in a multi-band 2D electron gas.

ORAL

Abstract

Recent experiments have established the phase diagrams of mono-, bilayer and ABC-stacked trilayer graphene at the charge neutrality, but that in more complex cases of graphene multiband structures such as ABA-stacked trilayer graphene (TLG) have not been thoroughly investigated. We report transport studies in ABA-TLG where the effect of Coulomb interactions plays a crucial role in formation of the different orbital/spin/valley symmetries. We explore theoretically and experimentally the effect of magnetic and displacement fields on these symmetries within the $\nu {\rm g}=$ 0 quantum Hall state. Our experimental results indicate at least 5 different phases arise from multiband nature of TLG, with conductance ranging from 0.1e$^{\mathrm{2}}$/h, 2e$^{\mathrm{2}}$/h to 4e$^{\mathrm{2}}$/h, reflecting the rich interplay between crystal symmetry and Coulomb interactions.

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Authors

  • Petr Stepanov

    • Univ of California - Riverside

  • Yafis Barlas

    • Univ of California - Riverside

  • Chun Ning Lau

    • Univ of California - Riverside

  • Dmitry Smirnov

    • National High Magnetic FIeld Laboratory
    • National High Magnetic Field Lab

  • Kenji Watanabe

    • National Institute for Materials Science, 1-1 Namiki, Tsukuba, Ibaraki, 305-0044 JAPAN
    • National Institute for Material Science, Japan
    • National Institute for Materials Science
    • National Institute for Materials Science, Japan
    • Advanced materials laboratory, National institute for Materials Science, Tsukuba, Ibaraki, 305-0044, Japan
    • NIMS, Tsukuba, Japan

  • Takashi Taniguchi

    • National Institute for Materials Science, 1-1 Namiki, Tsukuba, Ibaraki, 305-0044 JAPAN
    • National Institute for Material Science, Japan
    • National Institute for Materials Science
    • National Institute for Materials Science, Japan
    • Advanced materials laboratory, National institute for Materials Science, Tsukuba, Ibaraki, 305-0044, Japan
    • NIMS, Tsukuba, Japan

  • Maxim Kharitonov

    • University of Würzburg, Germany

  • Fan Zhang

    • University of Texas, Dallas
    • UT Dallas
    • Department of Physics, University of Texas at Dallas

  • A. H. MacDonald

    • The University of Texas at Austin
    • Department of Physics, University of Texas at Austin, Texas 78712, USA
    • UT Austin
    • Univ of Texas, Austin
    • Department of Physics, University of Texas at Austin
    • Department of Physics, University of Texas at Austin, TX 78712, USA