Helical trilayer graphene: a moiré platform for strongly-interacting topological bands – Part 2

ORAL

Abstract

The combination of strong electronic correlations and non-trivial band topology is fertile ground for exotic electronic phenomena. Here, we explore topological flat bands that emerge in magic angle helical trilayer graphene (HTG), which comprises three layers of graphene with successive layers rotated in the same direction by the same relative twist angle, θm ≈ 1.8°. We find correlated states and anomalous Hall effect at multiple integer and fractional electron fillings per moiré unit cell. At the filling of one electron per moiré unit cell, a time-reversal symmetric phase appears beyond a critical electric displacement field, indicating a topological phase transition. Finally, hysteresis upon sweeping carrier density points to first-order phase transitions across a spatial mosaic of Chern domains separated by a network of topological gapless edge states. We establish HTG as an ideal platform for exploring orbital magnetism with Chern domain walls, and a promising system for realizing exotic strongly interacting topological phases.

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Publication: Li-Qiao Xia, Sergio C. de la Barrera, Aviram Uri, Aaron Sharpe, Yves H. Kwan, Ziyan Zhu, Kenji Watanabe, Takashi Taniguchi, David Goldhaber-Gordon, Liang Fu, Trithep Devakul, and Pablo Jarillo-Herrero, Helical trilayer graphene: a moiré platform for strongly-interacting topological bands (2023), arXiv: 2310.12204 [cond-mat.mes-hall].

Presenters

  • Liqiao Xia

    • Massachusetts Institute of Technology

Authors

  • Liqiao Xia

    • Massachusetts Institute of Technology

  • Sergio C de la Barrera

    • Massachusetts Institute of Technology MI

  • Aviram Uri

    • Massachusetts Institute of Technology
    • MIT

  • Aaron L Sharpe

    • Stanford University
    • Sandia National Laboratories

  • Yves Hon H Kwan

    • Princeton University

  • Ziyan Zhu

    • Stanford University

  • 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

  • David Goldhaber-Gordon

    • Stanford University
    • Stanford Institute for Materials and Energy Sciences, Stanford University Physics Department
    • Department of Physics, Stanford University, Stanford, California
    • Stanford Institute for Materials & Energy Sciences, Stanford University

  • Liang Fu

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

  • Trithep Devakul

    • Stanford University

  • Pablo Jarillo-Herrero

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