Broken Symmetry States in Twisted Bilayer Graphene

ORAL

Abstract

Graphene bilayer with multiple degeneracy provides an access to rich quantum Hall states (QHS) with broken symmetry, arising from electron-electron interactions and Zeeman splitting. Here, we present quantum Hall effect in high-quality twisted bilayer graphene. At high density regime, we found several QH plateaus are suppressed or emerged with magnetic fields, indicating transitions between different QH states. We ascribe this to imperfect screening of twisted bilayer, which results in different Landau levels formation on each layer and their mixings. As low density regime, odd integer QHS are observed, suggesting an important role of the interlayer charge transfer for stabilizing broken symmetry QHS

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Authors

  • Youngwook Kim

    • Department of Physics, Pohang University of Science and Technology, Korea

  • Jong Mok Ok

    • Department of Physics, Pohang University of Science and Technology, Korea

  • Jun Sung Kim

    • Department of Physics, Pohang University of Science and Technology, Korea

  • Jaesung Park

    • Center for Quantum Measurements, Korea Research Institute of Standards and Science, Korea

  • Suyong Jung

    • Center for Quantum Measurements, Korea Research Institute of Standards and Science, Korea

  • Dong Su Lee

    • Soft Innovative Materials Research Center, Korea Institute of Science and Technology, Korea

  • Intek Song

    • Department of Chemistry and Division of advanced Materials Science, Pohang University of Science and Technology, Korea

  • Hee Cheul Choi

    • Department of Chemistry and Division of advanced Materials Science, Pohang University of Science and Technology, Korea

  • K. Watanabe

    • National Institute for Materials Science, Japan

  • T. Taniguchi

    • National Institute for Materials Science, Japan