Helical trilayer graphene: a moiré platform for strongly-interacting topological bands – Part 1

ORAL

Abstract

Topological bands in two dimensional materials can be promoted by broken xy-inversion (C2z) symmetry. Existing examples include materials where the constituent layers break C2z on their own. Here, we explore helical trilayer graphene (HTG), three graphene layers, each preserving C2z on their own, twisted in sequence by the same angle. Unlike alternating-twist trilayer graphene, this forms two moiré patterns with different orientations. Although HTG is globally C2z-symmetric, lattice relaxation leads to large periodic domains in which C2z is broken on the moiré scale. Using magnetotransport, we observe the anomalous Hall effect – a clear signature of topological bands. At a magic angle of θm ≈ 1.8°, we uncover a robust phase diagram of correlated and magnetic states. Our results bring to light the importance of local symmetries on length scales comparable to the inter-particle distance, n-1/2.

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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

  • Aviram Uri

    • Massachusetts Institute of Technology
    • MIT

Authors

  • Aviram Uri

    • Massachusetts Institute of Technology
    • MIT

  • Liqiao Xia

    • Massachusetts Institute of Technology

  • Sergio C de la Barrera

    • Massachusetts Institute of Technology MI

  • 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