Nanoscale Imaging of moiré excitons in WS<sub>2</sub>/WSe<sub>2</sub> heterostructures using low-loss EELS.

ORAL

Abstract

After the discovery of superconductivity in magic angle bilayer graphene, there is tremendous interest to explore new electronic states arising in 2D heterostructures due to the moiré superlattice potential.1 Signatures of moiré excitons in 2D semiconductor heterostructures of transition metal dichalcogenides have typically been  probed using far-field optical techniques.    However, the nature of the moiré excitons is difficult to probe using these techniques.Theoretically, these excitons are predicted to have interesting spatial modulations within the moiré unit-cell. In this study, we use low-loss electron energy loss spectroscopy to probe excitons in rotationally aligned WS2/WSe2 heterostructures with nanometer-scale spatial resolution to experimentally determine the spatial distribution of the moiré excitons in the superlattice.

*Work preseneted in this work was performed at the Molecular Foundry that is supported by the Office of Science, Office of Basic Energy Sciences, of the U.S. Department of Energy under Contract No. DE-AC02-05CH11231. S.S was supperted by Quantum Materials program from the Basic Energy Sciences, Office of Science at the Department of Energy

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Publication: 1. Kennes, D. M. et al. Moiré heterostructures as a condensed-matter quantum simulator. Nat. Phys. 17, 155–163 (2021).

Presenters

  • Sandhya Susarla

    • Lawrence Berkeley National Lab
    • Lawrence Berkeley National Laboratory
    • Lawrence Berkeley National laboratory

Authors

  • Sandhya Susarla

    • Lawrence Berkeley National Lab
    • Lawrence Berkeley National Laboratory
    • Lawrence Berkeley National laboratory

  • Daria Blach

    • Purdue University
    • Department of Chemistry, Purdue University

  • Mit H Naik

    • University of California, Berkeley
    • University of California at Berkeley and Lawrence Berkeley National Laboratory
    • University of California at Berkeley and Lawrence Berkeley National Lab

  • Zhenglu Li

    • University of California at Berkeley, and Lawrence Berkeley National Laboratory
    • Physics Department, UC Berkeley and Lawrence Berkeley National Lab
    • Lawrence Berkeley National Laboratory
    • Lawrence Berkeley National Laboratory; University of California at Berkeley
    • University of California at Berkeley and Lawrence Berkeley National Laboratory

  • Johan Carlstroem

    • Lawrence Berkeley National Laboratory

  • Takashi Taniguchi

    • National Institute for Materials Science, Tsukuba, Japan
    • National Institute for Materials Science
    • NIMS
    • Kyoto Univ
    • International Center for Materials Nanoarchitectonics, National Institute for Materials Science, 1-1 Namiki, Ibaraki 305-0044, Japan.
    • 3 National Institute for Materials Science, Tsukuba, Japan
    • National Institute for Materials Science; 1-1 Namiki, Tsukuba, Ibaraki 305-0044, Japan
    • National Institute of Materials Science, Tsukuba, Japan
    • National Institute of Materials Science
    • Advanced Materials Laboratory, National Institute for Materials Science, 1-1 Namiki, Tsukuba, 305-0044, Japan
    • National Institute for Materials Science (Japan)
    • International Center for Materials Nanoarchitectonics, National Institute for Materials Science
    • International Center for Materials Nanoarchitectonics, National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044, Japan
    • Kyoto University
    • International Center for Materials Nanoarchitectonics
    • International Center for Materials Nanoarchitectonics, National Institute for Materials Science, Tsukuba, Japan
    • International Center for Materials Nanoarchitectonics, National Institute for Materials Science, Japan
    • International Center for Materials Nanoarchitectonics, National Institute for MaterialsScience, 1-1 Namiki, Tsukuba 305-0044, Japan
    • National Institute for Material Science, Japan
    • National Institute for Material Science
    • National Institute of Material Sciences, Japan
    • NIMS, Tsukuba
    • 2National Institute for Materials Science, Namiki 1-1, Ibaraki 305-0044, Japan.
    • National Institute of Materials Science, Tsukuba, Ibaraki 305-0044, Japan
    • National Institute for Materials Science, Japan
    • International Center for Materials Nanoarchitectonics (WPI-MANA), National Institute for Materials Science, 1-1 Namiki Tsukuba, Ibaraki 305-0044, Japan.
    • NIMS, Japan
    • National Institute for Materials Science (NIMS)
    • NIMS. Japan
    • International Center for Material Nanoarchitectonics, National Institute for Materials Science, Tsukuba, Japan
    • International Center for Material Nanoarchitectonics, National Institute for Materials Science
    • National Institute for Materials Science Tsukuba
    • National Institute for Materials Science, 1-1 Namiki
    • National Institute for Materials Science of Japan
    • National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044, Japan
    • NIMS - National Institute for Material Science, Japan
    • International Center for Materials Nanoarchitectonics, National Institute for Material Science, Tsukuba, Ibaraki 305-0044, Japan.
    • National Institute for Material Science, Tsukuba
    • National Institute for Materials Science, International Center for Materials Nanoarchitectonics
    • International Center for Materials Nanoarchitectonics, National Institute for Materials Science, 1-1 Namiki, Tsukuba, Ibaraki 305-0044, Japan
    • National Institute of Material Science
    • National Institute for Materials Science,1-1 Namiki, Tsukuba, 305-0044, Japan

  • Kenji Watanabe

    • NIMS
    • Research Center for Functional Materials, National Institute for Materials Science
    • National Institute of Materials Science
    • National Institue for Materials Science
    • National Institute for Materials Science, Japan
    • National Institute for Materials Science (NIMS)
    • National Institute of Materials Science, Tsukuba, Japan
    • National Institute for Materials Science
    • NIMS, Japan

  • Libai Huang

    • Purdue University

  • Felipe H da Jornada

    • Stanford Univ
    • Stanford University

  • Ramamoorthy Ramesh

    • University of California, Berkeley

  • Steven G Louie

    • University of California at Berkeley, and Lawrence Berkeley National Laboratory
    • Physics Department, UC Berkeley and Lawrence Berkeley National Lab
    • University of California Berkeley
    • University of California, Berkeley
    • University of California at Berkeley; Lawrence Berkeley National Laboratory
    • University of California at Berkeley and Lawrence Berkeley National Laboratory
    • UC berkeley
    • University of California at Berkeley and Lawrence Berkeley National Lab
    • UC Berkeley & Lawrence Berkeley National Laboratory

  • Peter Ercius

    • Berkeley National Laboratory
    • Lawrence Berkeley National Laboratory

  • Archana Raja

    • Lawrence Berkeley National Laboratory