Superconductivity and correlated states in twisted bilayer graphene-WSe<sub>2</sub> heterostructures: Part 2

ORAL

Abstract

Magic-angle twisted bilayer graphene (TBG) hosts a multitude of correlated insulating, superconducting, and topological phases. We show that adding an insulating monolayer of WSe2 to the TBG stabilizes superconductivity down to angles as small as 0.79°. At angles in this range, both the correlated insulating states and the band gaps between flat and dispersive bands disappear, leading to metallic behavior across the accessible range of electron density. We additionally observe weak antilocalization and the breaking of the fourfold spin-valley symmetry usually observed in TBG, consistent with strong spin-orbit coupling. Further, in-plane and out-of-plane magneto-transport measurements reveal that finite-field correlated phases also persist for twist angles well below the magic angle value. Our results constrain theoretical explanations for the superconductivity and correlated insulators in TBG and emphasize the importance of the dielectric substrates for engineering of the electronic states in moiré systems.

*National Science Foundation through program CAREER DMR-1753306 and the IQIM (NSF-funded Physics Frontiers Center). Also supported in part by the Kavli Nanoscience Institute (KNI) at Caltech and the US Department of Energy DOE-QIS program (DE-SC0019166).

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Presenters

  • Robert Polski

    • Caltech
    • Watson Laboratory of Applied Physics, California Institute of Technology
    • Physics, California Institute of Technology

Authors

  • Robert Polski

    • Caltech
    • Watson Laboratory of Applied Physics, California Institute of Technology
    • Physics, California Institute of Technology

  • Yiran Zhang

    • Caltech
    • Department of Physics, California Institute of Technology

  • Harpreet Arora

    • Caltech
    • Watson Laboratory of Applied Physics, California Institute of Technology

  • Alex R Thomson

    • Caltech
    • Department of Physics, California Institute of Technology

  • Youngjoon Choi

    • Caltech
    • Department of Physics, California Institute of Technology

  • Hyunjin Kim

    • Caltech
    • Department of Physics, California Institute of Technology

  • Zhong Lin

    • University of Washington

  • Xiaodong Xu

    • Physics, University of Washington
    • Department of Physics, University of Washington
    • University of Washington
    • Department of Physics, University of Washington, Seattle
    • University of Washington, Seattle

  • Jiun-Haw Chu

    • University of Washington
    • Department of Physics, University of Washington, Seattle
    • Department of Physics, University of Washington
    • Physics, University of Washington

  • Kenji Watanabe

    • National Institute for Materials Science
    • National Institute for Materials Science, Japan
    • National Institure for Materials Science
    • Advanced Materials Laboratory, National Institute for Materials Science
    • NIMS
    • National Institute of Materials Science
    • National Institute for Materials Science (NIMS)
    • Research Center for Functional Materials, National Institute for Materials Science
    • National Institute for Materials Science,1-1 Namiki
    • National Institute of Material Science
    • National Institute for Materials Science, Tsukuba, Japan
    • Research Center for Functional Materials, NIMS
    • National Institute of Materials Science, Tsukuba, Japan
    • National Institude for Materials Science
    • National Institute for Materials Science, Tsukuba, Ibaraki, Japan
    • Research Center for Functional Materials, National Institute for Materials Science, Tsukuba 305-0044, Japan
    • International Center for Materials Nanoarchitectonics, National Institute for Materials
    • NIMS - Japan
    • National Institute for Materials Science ,Japan
    • National Institute for Materials Science, Tsukuba, 305-0044, Ibaraki, Japan
    • National Institute for Material Science
    • National Institute for Material Science, 1-1 Namiki, Tsukuba 305-0044, Japan
    • National Institute for Material Science Japan
    • NIMS Tsukuba
    • National Institute for Materials Science, Research Center for Functional Materials, Japan
    • Research Center for Functional Materials, National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044, Japan
    • National Institute for Materials Science: Namiki, Tsukuba, Ibaraki, JP
    • National Institue for Material Science
    • National Institute for Materials Science,1-1 Namiki, Tsukuba, 305-0044, Japan
    • Materials, NIMS
    • Research Center for Functional Materials, National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044, Japan, Research Center for Functional Materials, National In
    • Research Center for Functional Materials, Japan
    • International Center for Materials Nanoarchitectonics, National Institute for Materials Science
    • International Center for Materials nanoarchtectonics, National Institute for Materials Science, 1-1 Namiki, Tsukuba, 305-0044, Japan
    • NIMS Suguba
    • NIMS, Tsukuba, Japan
    • National Institute for Materials Science, Namiki 1-1, Tsukuba, 305-0044, Ibaraki, Japan
    • National institute of material science
    • Advanced Materials Laboratory, National Institute for Materials Science, 1-1 Namiki, Tsukuba, 305-0044, Japan
    • Advanced Materials Laboratory, NIMS
    • Research Center for Functional Materials, National Institute for Materials Science, Ibaraki, Japan
    • National Institute for Materials Science, Research Center for Functional Materials
    • National Institute of Material Science, Japan
    • Tsukuba, National Institute for Materials Science

  • Takashi Taniguchi

    • National Institute for Materials Science, Japan
    • National Institute for Materials Science
    • Department of Chemical Engineering, Kyoto University
    • National Institute for Materials Science, Tsukuba, Ibaraki, Japan
    • International Center for Materials Nanoarchitectonics, National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044, Japan
    • Materials, NIMS
    • International Center for Materials Anorthite, National Institute for Materials Science, Ibaraki, Japan
    • Kyoto University

  • Jason F. Alicea

    • Caltech
    • Department of Physics, California Institute of Technology
    • Department of Physics and Institute for Quantum Information and Matter; Walter Burke Institute for Theoretical Physics, California Institute of Technology

  • Stevan Nadj-Perge

    • Caltech
    • Watson Laboratory of Applied Physics, California Institute of Technology
    • Physics, California Institute of Technology