Highly tunable valley polarization of moiré excitons

ORAL

Abstract

Hetero-structures of transition metal dichalcogenide semiconductors stacked at near 0 (H) and 60 (R) degrees inherit the valley pseudo-spin from the monolayers. Here we investigate the valley properties of moiré excitons in the H- and R-stacked junctions and find that the valley polarization is highly tunable, much more so than the excitons in monolayer transition metal dichalcogenides. The exchange interaction is expected much weaker in the heterojunctions, due to the small overlap between electron and hole wavefunction for the interlayer exciton. Nevertheless, our experiments indicate that this weak exchange interaction can still play a dominant role in valley depolarization of the moiré excitons.

*This work is supported by NSF DMR 2004474.

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Presenters

  • Jun Yan

    • University of Massachusetts Amherst

Authors

  • Jun Yan

    • University of Massachusetts Amherst

  • Yueh-Chun Wu

    • Oak Ridge National Laboratory

  • Matthew DeCapua

    • University of Massachusetts Amherst

  • ZhongChen Xu

    • Institute of Physics, Chinese Academy of Sciences

  • Youguo Shi

    • Institute of Physics, Chinese Academy of Sciences
    • Chinese Academy of Sciences

  • Takashi Taniguchi

    • National Institute for Materials Science
    • International Center for Materials Nanoarchitectonics, National Institute for Materials Science
    • Research Center for Materials Nanoarchitectonics, National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044, Japan
    • International Center for Materials Nanoarchitectonics, National Institute of Material Science, Tsukuba, Japan
    • Advanced Materials Laboratory, National Institute for Materials Science

  • Kenji Watanabe

    • National Institute for Materials Science
    • NIMS
    • Research Center for Functional Materials, National Institute for Materials Science
    • Research Center for Electronic and Optical Materials, National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044, Japan
    • Research Center for Functional Materials, National Institute of Material Science, Tsukuba, Japan
    • National Institute of Materials Science
    • Advanced Materials Laboratory, National Institute for Materials Science