Tunability of Landau Level Crossings and Fractional Quantum Hall Phases in Few Layer Ballistic Graphene

ORAL

Abstract

Bernal stacked trilayer graphene (TLG) has four low energy mirror symmetric bands. These bands are very electric field sensitive because electric field breaks the original mirror symmetry with respect to the middle layer of TLG. Electric field hybridizes the bands and consequently the Landau level (LL) spectrum in presence of magnetic field gets modified. We study the dependence of the LLs in TLG on electric field. TLG has many naturally occurring LL crossings due to its differently dispersing bands. This provides a great platform for studying electric field effect in terms of its LL crossing locations in phase space. Electric field couples only a specific set of LLs which led to the observation of mostly crossings rather than avoided crossing at the degeneracy points. However, interestingly, we see signatures of valley coupling due to short range electronic interaction at the crossing point of two opposite valleys of zeroth LL (NM=0). These opposite valleys are brought into degeneracy by an electric field. We also observe some signatures of fractional quantum Hall effect in TLG.

*Swarnajayanthi Fellowship of Department of Science and Technology, Department of Atomic Energy of Government of India

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Presenters

  • Mandar Deshmukh

    • Tata Institute of Fundamental Research

Authors

  • Biswajit Datta

    • Tata Institute of Fundamental Research

  • Hitesh Agarwal

    • Tata Institute of Fundamental Research

  • Abhisek Samanta

    • Tata Institute of Fundamental Research

  • Amulya Ratnakar

    • Department of Physics, UM-DAE Centre for Excellence in Basic Sciences
    • Tata Institute of Fundamental 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

  • Rajdeep Sensarma

    • Department of Theoretical Physics, Tata Institute of Fundamental Reseach
    • Department of Theoretical Physics, Tata Institute of Fundamental Research
    • Tata Institute of Fundamental Research

  • Mandar Deshmukh

    • Tata Institute of Fundamental Research