Tunable heavy fermions in a moiré Kondo lattice

ORAL

Abstract

The formation of heavy electrons by merging a lattice of local magnetic moments to a sea of itinerant electrons is a profound problem in condensed matter physics. The emergence of moiré materials provides a new platform to explore this problem in simple and tunable fashions. Here we report the realization of a tunable Kondo lattice in AB-stacked MoTe2/WSe2 moiré bilayers. Heavy electrons are formed when the MoTe2 layer is tuned to a strongly correlated Mott insulator, which supports a triangular lattice of local magnetic moments, and the WSe2 layer is doped with itinerant carriers. Over ten-fold enhancement in the electron mass is observed when the itinerant carriers and local moments form Kondo singlets. The Kondo singlets can be destroyed by an external magnetic field; a sharpened destruction at low temperatures suggests the presence of quantum criticality. Our study lays the foundation for exploring the Doniach phase diagram in semiconductor moiré materials.

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Presenters

  • Wenjin Zhao

    • Cornell University, Kavli Institute at Cornell

Authors

  • Wenjin Zhao

    • Cornell University, Kavli Institute at Cornell

  • Bowen Shen

    • Cornell University

  • Zui Tao

    • Cornell University

  • Zhongdong Han

    • Cornell University

  • Kaifei Kang

    • Cornell University

  • Kenji Watanabe

    • National Institute for Materials Science
    • Research Center for Functional Materials, National Institute of Materials Science
    • Research Center for Functional Materials, National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-044, Japan
    • NIMS
    • Research Center for Functional Materials, National Institute for Materials Science
    • National Institute for Materials Science, Japan
    • Research Center for Functional Materials, National Institute for Materials Science, Tsukuba, Japan
    • NIMS Japan

  • Takashi Taniguchi

    • National Institute for Materials Science
    • Kyoto Univ
    • International Center for Materials Nanoarchitectonics, National Institute of Materials Science
    • Kyoto University
    • International Center for Materials Nanoarchitectonics, National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-044, Japan
    • International Center for Materials Nanoarchitectonics, National Institute for Materials Science
    • National Institute for Materials Science, Japan
    • National Institute For Materials Science
    • NIMS
    • National Institute for Material Science
    • International Center for Materials Nanoarchitectonics, National Institute for Materials Science, Tsukuba, Japan
    • NIMS Japan

  • Kin Fai Mak

    • Cornell University

  • Jie Shan

    • Cornell University