Evidence of Moiré Excitons in van der Waal(vdW) Heterostructure

ORAL

Abstract

We report spectroscopy evidence of interlayers excitons confined by a moire superlattice in hBN encapsulated MoSe2/WSe2 heterostructures with small twist angles. Low temperature photoluminescence(PL) measurement shows that interlayer exciton splits into multiple peaks with alternating circular polarization. We assign these peaks to the ground state and excited state excitons localized within a Moiré supercell and explain how the spatial variation of optical selection rule can give rise to multiple peaks with alternative circular polarization. Temperature dependence PL, twist angle dependence, and recombination dynamics all agrees with the localized exciton picture. Our results suggest the feasibility of engineering artificial excitonic crystal using vdW heterostructures for nanophotonics and quantum information applications.

*We gratefully acknowledge funding support from NSF MRSEC under grant DMR-1720595, NSF EFMA-1542747, NSF DMR-1306878, Welch Foundation via grant F-1662, Army Research Office (ARO) #W911NF-17-1-0312 (MURI), Air Force Office of Scientific Research (AFOSR) FA9550-17-1-0304 and NSF DMR-1455346, Japan Elemental Strategy Initiative grant No. JP15K21722.

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Presenters

  • Kha Tran

    • University of Texas at Austin
    • Department of Physics, University of Texas at Austin, TX 78712, United States

Authors

  • Kha Tran

    • University of Texas at Austin
    • Department of Physics, University of Texas at Austin, TX 78712, United States

  • Galan Moody

    • NIST

  • Fengcheng Wu

    • Argonne National Lab
    • Condensed Matter Theory Center, University of Maryland
    • University of Maryland

  • Xiaobo Lu

    • Beijing National Laboratory for Condensed Matter Physics, Beijing, China
    • Chinese Academy of Science
    • Physics, Washington University in St. Louis

  • Junho Choi

    • University of Texas at Austin
    • Department of Physics, University of Texas at Austin, TX 78712, United States

  • Jiamin Quan

    • University of Texas at Austin
    • Department of Physics, The University of Texas at Austin
    • Department of Physics, The University of Texas at Austin, USA

  • Akshay Singh

    • Massachusetts Institute of Technology

  • Jacob S Embley

    • University of Texas at Austin

  • André Zepeda

    • University of Texas at Austin
    • Department of Physics, University of Texas at Austin, TX 78712, United States

  • Marshall Campbell

    • University of Texas at Austin
    • Department of Physics, University of Texas at Austin, TX 78712, United States

  • Kyounghwan Kim

    • Electrical and Computer Engineering department, The University of Texas at Austin
    • University of Texas at Austin

  • Amritesh Rai

    • University of Texas at Austin

  • Travis Autry

    • NIST

  • Daniel Sanchez

    • University of Texas at Austin

  • 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

  • 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

  • Nanshu Lu

    • University of Texas at Austin

  • Sanjay Banerjee

    • University of Texas at Austin

  • Emanuel Tutuc

    • Electrical and Computer Engineering department, The University of Texas at Austin
    • University of Texas at Austin

  • Suenne Kim

    • Hanyang University

  • Li Yang

    • Physics, Washington University in St. Louis
    • Physics, Washington University, St. Louis

  • Kevin Silverman

    • NIST

  • Allan MacDonald

    • Department of Physics, University of Texas at Austin
    • University of Texas at Austin
    • The University of Texas at Austin

  • Xiaoqin (Elaine) Li

    • University of Texas at Austin
    • University of Texas-Austin
    • The University of Texas at Austin
    • Department of Physics and Center for Complex Quantum Systems, Univ of Texas, Austin
    • Department of Physics, University of Texas at Austin, TX 78712, United States
    • Univ of Texas, Austin
    • Department of Physics, The University of Texas at Austin
    • Department of Physics, The University of Texas at Austin, USA