Gate-Tunable Mott Insulator in Trilayer Graphene-Boron Nitride Moiré Superlattice

ORAL

Abstract

Mott insulator plays a central role in strongly correlated physics, where the repulsive Coulomb interaction dominates over the electron kinetic energy and leads to insulating states with one electron occupying each unit cell. A tunable Mott insulator, where the competition between the Coulomb interaction and the kinetic energy can be varied in situ, can provide an invaluable model system for the study of Mott physics. Here we report the realization of such a tunable Mott insulator in the ABC trilayer graphene (TLG) and hexagonal boron nitride (hBN) heterostructure with a Moiré superlattice. The Moiré superlattice in TLG/hBN heterostructures leads to narrow electronic minibands that are gate-tunable. The Mott insulator states emerge at 1/4 and 1/2 fillings, corresponding to one electron and two electrons per site, respectively. Moreover, the Mott states in the ABC TLG/hBN heterostructure exhibit unprecedented tunability: the Mott gap can be modulated in situ by a vertical electrical field, and at the meantime the electron doping can be gate-tuned to fill the band from one Mott insulating state to another. Our observation opens up tremendous opportunities to explore novel strongly correlated phenomena in two-dimensional Moiré superlattice heterostructures.

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Presenters

  • Guorui Chen

    Physics, UC Berkeley, Department of Physics, University of California at Berkeley, Berkeley, CA 94709, USA

Authors

  • Guorui Chen

    Physics, UC Berkeley, Department of Physics, University of California at Berkeley, Berkeley, CA 94709, USA

  • Lili Jiang

    Physics, UC Berkeley, UC Berkeley

  • Shuang Wu

    Electrical Engineering and Computer Sciences, UC Berkeley

  • Bosai Lv

    Physics, Shanghai Jiaotong University, Shanghai Jiao Tong University

  • Hongyuan Li

    Physics, Shanghai Jiaotong University, Shanghai Jiao Tong University

  • Kenji Watanabe

    National Institute for Materials Science, 1-1 Namiki, Tsukuba, Ibaraki 305 0044, Japan, Advanced Materials Laboratory, National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044, Japan, National Institute for Materials Science, Advanced Materials Laboratory, National Institute for Materials Science, , 1-1 Namiki, Tsukuba 305-0044, Japan, National Institute for Material Science, 1-1 Namiki, Tsukuba 305-0044, National Institute of Materials Science, NIMS, Japan, Advanced Materials Laboratory, NIMS, National Institute for Materials Science, Tsukuba, Japan, National Institute for Materials Science, Japan, Advanced Materials Laboratory, National Institute for Materials Science, National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044, Japan, National Institute for Materials Science, 1-2-1 Sengen, Tsukuba, Ibaraki 305-0044, Japan, National Institute for Materials Science (NIMS), NIMS Tsukuba, National Institute for Materials Science (Japan), NIMS, National Institute for Material Science, National Institute for Materials Science, 1-1 Namiki, Tsukuba, Japan, National Institute for Materials Science , Japan, National Institute for Materials Science, Namiki 1-1, Tsukuba, Ibaraki 305-0044, Japan., Advanced Materials Laboratory, National Institute for Materials Science, Japan, Advanced Materials Laboratory, National Institute for Materials Science, Tsukuba, Ibaraki 305-0044, Japan, National Institute for Materials Science, Tsukuba, Ibaraki 305- 0044, Japan, National Institute for Material Science - Japan, National Institute for Materials Science, Namiki Tsukuba Ibaraki, Japan, National Institute of Material Science, Advanced Material Lab, NIMS, Advanced Materials Laboratory, National Institute for Materials Science, Tsukuba, Japan, Advanced Materials Laboratory, National Institute for Materials Science, Tsukuba, Ibaraki, Japan, National Institute for Materials Science, Tsukuba, 1-1 Namiki, Tsukuba, National Institute for Materials Science, NIMS/Tsukuba, National Institute for Materials Science, 1-1 Namiki, Tsukuba, 305-0044 Japan, National Institute for Materials Science, Namiki, 305-0044, Japan, National Institute for Material Science, Japan, Advanced Materials Laboratory, NIMS, Japan, Columbia University, Advanced Materials Labaratory, National Institute for Materials Science, National Institute of Material Science, 1-1 Namiki, Tsukuba, Ibaraki 205-0044, Japan, National Institute of Materials Science, Japan

  • Takashi Taniguchi

    National Institute for Materials Science, 1-1 Namiki, Tsukuba, Ibaraki 305 0044, Japan, National Institute for Materials Science, Advanced Materials Laboratory, National Institute for Materials Science, , 1-1 Namiki, Tsukuba 305-0044, Japan, National Institute for Material Science, 1-1 Namiki, Tsukuba 305-0044, National Institute of Materials Science, NIMS, Japan, Advanced Materials Laboratory, NIMS, National Institute for Materials Science, Tsukuba, Japan, Advanced Materials Laboratory, National Institute for Materials Science, National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044, Japan, National Institute for Materials Science, 1-2-1 Sengen, Tsukuba, Ibaraki 305-0044, Japan, National Institute for Materials Science (NIMS), NIMS Tsukuba, NIMS, National Institute for Material Science, National Institute for Materials Science, Japan, National Institute for Materials Science, 1-1 Namiki, Tsukuba, Japan, National Institute for Materials Science , Japan, Advanced Materials Laboratory, National Institute for Materials Science, Japan, Advanced Materials Laboratory, National Institute for Materials Science, Tsukuba, Ibaraki 305-0044, Japan, National Institute for Materials Science, Tsukuba, Ibaraki 305- 0044, Japan, National Institute for Material Science - Japan, National Institute for Materials Science, Namiki Tsukuba Ibaraki, Japan, National Institute of Material Science, Advanced Material Lab, NIMS, Advanced Materials Laboratory, National Institute for Materials Science, Tsukuba, Japan, Advanced Materials Laboratory, National Institute for Materials Science, Tsukuba, Ibaraki, Japan, National Institute for Materials Science, Tsukuba, 1-1 Namiki, Tsukuba, National Institute for Materials Science, NIMS/Tsukuba, National Institute for Materials Science, 1-1 Namiki, Tsukuba, 305-0044 Japan, National Institute for Materials Science, Namiki, 305-0044, Japan, National Institute for Material Science, Japan, Advanced Materials Laboratory, NIMS, Japan, Advanced Materials Labaratory, National Institute for Materials Science, National Institute of Material Science, 1-1 Namiki, Tsukuba, Ibaraki 205-0044, Japan, National Institute of Materials Science, Japan

  • Zhiwen Shi

    Physics, Shanghai Jiaotong University, Shanghai Jiao Tong University

  • Yuanbo Zhang

    Fudan University, State Key Laboratory of Surface Physics and Department of Physics, Fudan University, Institute for Nanoelectronic Devices and Quantum Computing, Fudan University, Shanghai 200433, China, Dept. of Physics, Fudan University, Physics Department, Fudan University

  • Feng Wang

    University of California - Berkeley, University of California, Berkeley, Physics, UC Berkeley, Department of Physics, University of California at Berkeley, Berkeley, CA 94709, USA, University of California at Berkeley, Lawrence Berkeley National Laboratory and UC Berkeley, UC Berkeley, Physics, University of California, Berkeley