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Visualization of the flat electronic band in twisted bilayer graphene near the magic angle twist

ORAL

Abstract

Bilayer graphene was theorized to host a moiré miniband with flat dispersion if the layers are stacked at specific twist angles known as the “magic angles”. Recently, such twisted bilayer gra-phene (tBLG) with the first magic angle twist was reported to exhibit correlated insulating state and superconductivity, where the presence of the flat miniband in the system is thought to be es-sential for the emergence of these ordered phases in the transport measurements. Tunneling spectroscopy and electronic compressibility measurements in tBLG have revealed a van Hove sin-gularity that is consistent with the presence of the flat miniband. However, a direct observation of the flat dispersion in the momentum-space of such moiré miniband in tBLG is still elusive. Here, we report the visualization of the flat moiré miniband by using angle-resolved photoemission spectros-copy with nanoscale resolution (nanoARPES). The high spatial resolution in nanoARPES enabled the measurement of the local electronic structure of the tBLG. We clearly demonstrate the exist-ence of the flat moiré band near the charge neutrality for tBLG close to the magic angle at room temperature.

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Presenters

  • Iqbal Utama

    University of California, Berkeley, Department of Physics, University of California, Berkeley

Authors

  • Iqbal Utama

    University of California, Berkeley, Department of Physics, University of California, Berkeley

  • Roland Koch

    Advanced Light Source, Lawrence Berkeley National Laboratory, Lawrence Berkeley National Laboratory, Advanced Light Source

  • Kyunghoon Lee

    University of California, Berkeley

  • Nicolas Leconte

    Department of Physics, University of Seoul, Physics, University of Seoul

  • Hongyuan Li

    University of California, Berkeley, Department of Physics, University of California, Berkeley

  • Sihan Zhao

    University of California, Berkeley, Department of Physics, University of California, Berkeley

  • Lili Jiang

    University of California, Berkeley, Department of Physics, University of California, Berkeley

  • jiayi zhu

    University of California, Berkeley

  • Kenji Watanabe

    National Institute for Materials Science, Japan, National Institute for Material Science, National Institute for Materials Science, National Institute for Materials Science, Tsukuba, Research Center for Functional Materials, NIMS, nims, Advanced Materials Laboratory, National Institute for Materials Science, National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044, Japan, NIMS, National Institute for Material Science - Japan, NIMS Tsukuba, National Institute for Materials Science, Namiki 1-1, Ibaraki 305-0044, Japan., National Institute for Materials Science (NIMS), National Institute for Materials Science,Tsukuba, Ibaraki 305-0047, Japan, Advanced Materials Laboratory, NIMS, Japan, National Institute for Materials Science,1-1 Namiki, Tsukuba, 305-0044, Japan, National Institute of Materials Science, National Institute for Materials Science, University of Tsukuba, National Institute for Materials Science, Tsukuba, Japan, National Institute for Material Science, Japan, National Institue for Material Science, Tsukuba, Advanced Materials Laboratory, NIMS, Advanced Materials Laboratory, National Institute for Materials Science, Tsukuba 305-0044, Japan, Advanced Matrials Lab, NIMS, National Institute for Material Science, Tsukuba, Japan, National institute for materials science, NIMS-Tsukuba, NIMS, Japan, National Institute for Materials Science, Namiki Tsukuba Ibaraki, Japan, NIRM, Advanced Materials Laboratory, National Institute for Materials Science, Tsukuba, Japan, NIMS Japan, National Institute for Materials Science, Tsukuba, Ibaraki 305-0044, Japan, Research Center for Functional Materials, National Institute for Materials Science, Tsukuba, Ibaraki, Japan, Advanced Materials Laboratory, National Institute of Materials Science, Advanced Materials Laboratory, National Institute for Materials Science 1-1 Namiki, Tsukuba, 305-0044, Japan, National Institute of Material Science, 1-1 Namiki, Tsukuba 305-0044, Japan, National Institute for Material Science (Japan), Physics, NIMS, National Institute of Materials Science, Japan, National Institute of Materials Science (NIMS), National Institute of Materials Science, Tsukuba, Ibaraki 305-0044, Japan, NIMS - Tsukuba

  • Takashi Taniguchi

    National Institute for Materials Science, Japan, National Institute for Material Science, National Institute for Materials Science, National Institute for Materials Science, Tsukuba, Research Center for Functional Materials, NIMS, nims, Advanced Materials Laboratory, National Institute for Materials Science, National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044, Japan, NIMS, National Institute for Material Science - Japan, NIMS Tsukuba, National Institute for Materials Science, Namiki 1-1, Ibaraki 305-0044, Japan., National Institute for Materials Science (NIMS), National Institute for Materials Science,Tsukuba, Ibaraki 305-0047, Japan, Advanced Materials Laboratory, NIMS, Japan, National Institute for Materials Science,1-1 Namiki, Tsukuba, 305-0044, Japan, National Institute of Materials Science, National Institute for Materials Science, University of Tsukuba, National Institute for Materials Science, Tsukuba, Japan, National Institue for Material Science, Tsukuba, Advanced Materials Laboratory, NIMS, Advanced Materials Laboratory, National Institute for Materials Science, Tsukuba 305-0044, Japan, Advanced Matrials Lab, NIMS, National Institute for Material Science, Tsukuba, Japan, National institute for materials science, NIMS-Tsukuba, NIMS, Japan, National Institute for Materials Science, Namiki Tsukuba Ibaraki, Japan, Advanced Materials Laboratory, National Institute for Materials Science, Tsukuba, Japan, NIMS Japan, National Institute for Materials Science, Tsukuba, Ibaraki 305-0044, Japan, Research Center for Functional Materials, National Institute for Materials Science, Tsukuba, Ibaraki, Japan, Advanced Materials Laboratory, National Institute of Materials Science, Advanced Materials Laboratory, National Institute for Materials Science 1-1 Namiki, Tsukuba, 305-0044, Japan, National Institute of Material Science, 1-1 Namiki, Tsukuba 305-0044, Japan, National Institute for Material Science (Japan), Physics, NIMS, National Institute of Materials Science, Japan, National Institute of Materials Science, Tsukuba, Ibaraki 305-0044, Japan, NIMS - Tsukuba

  • paul ashby

    Molecular Foundry, Lawrence Berkeley National Laboratory, Lawrence Berkeley National Laboratory

  • Alexander Weber-Bargioni

    Lawrence Berkeley National Laboratory, Molecular Foundry, Lawrence Berkeley National Laboratory

  • Alex Zettl

    Lawrence Berkeley National Lab and UC Berkeley, University of California, Berkeley, Department of Physics, University of California, Berkeley

  • Chris Jozwiak

    Advanced Light Source, Lawrence Berkeley National Lab, Lawrence Berkeley National Laboratory, Advanced Light Source, Lawrence Berkeley National Laboratory, Advanced Light Source, E. O. Lawrence Berkeley National Laboratory, ALS, Lawrence Berkeley National Lab, Advanced Light Source

  • Jeil Jung

    University of Seoul, Department of Physics, University of Seoul

  • Eli Rotenberg

    Advanced Light Source, Lawrence Berkeley National Laboratory, Lawrence Berkeley National Laboratory, Advanced Light Source, Lawrence Berkeley National Lab, Advanced Light Source, E. O. Lawrence Berkeley National Laboratory, ALS, Lawrence Berkeley National Lab, Advanced Light Source

  • Aaron Bostwick

    Advanced Light Source, Lawrence Berkeley National Laboratory, Lawrence Berkeley National Laboratory, Advanced Light Source, Lawrence Berkeley National Lab, Advanced Light Source, E. O. Lawrence Berkeley National Laboratory, ALS, Lawrence Berkeley National Lab, Advanced Light Source

  • Feng Wang

    University of California at Berkeley, University of California, Berkeley, UC Berkeley, Physics, University of California, Berkeley, University of California, Berkeley and MSD, LBNL, Department of Physics, University of California, Berkeley