Fractional Quantum Anomalous Hall Effect in Multilayer Graphene

ORAL

Abstract

The fractional quantum anomalous Hall effect (FQAHE)1, the analog of the fractional quantum Hall effect at zero magnetic field, is predicted to exist in topological flat bands under spontaneous time-reversal-symmetry breaking2-5. The demonstration of FQAHE could lead to non-Abelian anyons which form the basis of topological quantum computation6-8. So far, FQAHE has been observed only in twisted MoTe2 (t-MoTe2) at moiré filling factor v > 1/29-12. Graphene-based moiré superlattices are believed to host FQAHE with the potential advantage of material quality and electron mobility. In this talk, I will report the observation of integer and fractional QAH effects in a rhombohedral pentalayer graphene/hBN moiré superlattice. At zero magnetic field, we observed plateaus of quantized Hall resistance Rxy = h/(ve2) at moiré filling factors v = 1, 2/3, 3/5, 4/7, 4/9, 3/7 and 2/5. In addition, the phase transitions from composite Fermi liquid and FQAH states to other correlated states will also be discussed. The rich family of FQAH states in our graphene-based moiré superlattice provides an ideal platform for exploring charge fractionalization and (non-Abelian) anyonic braiding at zero magnetic field13-18.

*L.J. acknowledges support from a Sloan Fellowship. Work by T.H., J.Y. and J.S. was supported by NSF grant no. DMR- 2225925. The device fabrication of this work was supported by the STC Center for Integrated Quantum Materials, NSF grant no. DMR-1231319 and was carried out at the Harvard Center for Nanoscale Systems and MIT.Nano. Part of the device fabrication was supported by USD(R&E) under contract no. FA8702-15-D-0001. K.W. and T.T. acknowledge support from the JSPS KAKENHI (Grant Numbers 20H00354, 21H05233 and 23H02052) and World Premier International Research Center Initiative (WPI), MEXT, Japan. L.F. was supported by the STC Center for Integrated Quantum Materials (CIQM) under NSF award no. DMR-1231319.

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13. Nature Physics. 16:9 16, 931–936 (2020).
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Presenters

  • Zhengguang Lu

    • Massachusetts Institute of Technology

Authors

  • Zhengguang Lu

    • Massachusetts Institute of Technology

  • Tonghang Han

    • Massachusetts Institute of Technology

  • Yuxuan Yao

    • Massachusetts Institute of Technology

  • Aidan Reddy

    • Massachusetts Institute of Technology MI

  • Jixiang Yang

    • Massachusetts Institute of Technology MIT

  • Junseok Seo

    • Massachusetts Institute of Technology

  • Kenji Watanabe

    • National Institute for Materials Science
    • NIMS
    • Research Center for Electronic and Optical Materials, National Institute for Materials Science
    • Research Center for Functional Materials, National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044, Japan
    • National Institute for Material Science

  • Takashi Taniguchi

    • Kyoto Univ
    • National Institute for Materials Science
    • Research Center for Materials Nanoarchitectonics
    • Research Center for Materials Nanoarchitectonics, National Institute for Materials Science
    • National Institute for Materials Sciences
    • NIMS
    • International Center for Materials Nanoarchitectonics, National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044, Japan
    • National Institute for Material Science
    • International Center for Materials Nanoarchitectonics, NIMS, Japan
    • International Center for Materials Nanoarchitectonics, Tsukuba
    • National Institue for Materials Science
    • Kyoto University
    • National Institute of Materials Science
    • International Center for Materials Nanoarchitectonics and National Institute for Materials Science

  • Liang Fu

    • Massachusetts Institute of Technology MI
    • Massachusetts Institute of Technology
    • MIT

  • Long Ju

    • Massachusetts Institute of Technology