Correlated States in Twisted Bilayer WSe<sub>2 </sub>at Integer and Fractional Charges per Moiré Unit Cell

ORAL

Abstract

The discovery of flat bands in magic-angle twisted bilayer graphene (MATBG) opened a new field of correlated physics research, revealing correlated insulating phases and superconductivity. Similar to MATBG, moiré systems based on transition metal dichalcogenides (TMDs) such as twisted MoTe2 and WSe2, can host flat bands over a wider range of twist angles. Here we investigate the transport characteristics in small-angle twisted bilayer WSe2, with twist angles between 2˚ and 3˚. Our devices feature a dual-gate structure with graphite gates, which enables independent control of the carrier density and the displacement field. Remarkably, at zero magnetic field we observe signatures of correlated states when the number of carriers per moiré unit cell (ν) is integer, for ν = 2 and ν = 3, as well as fractional, for ν = 5/3, 7/3, 8/3. The correlated states at fractional ν survive up to 5 K, while the correlated states at integer ν survive up to 20 K.

*The work at The University of Texas at Austin was supported by the National Science Foundation (NSF) Grants No. MRSEC DMR-2308817 and No. ECCS-2122476, Army Research Office under Grant No. W911NF-22-1-2, and the Welch Foundation Grant No. F-2169-20230405.

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Presenters

  • Taeran Lee

    • University of Texas at Austin
    • Microelectronics Research Center, Department of Electrical and Computer Engineering, The University of Texas at Austin, Austin, Texas 78758, USA

Authors

  • Taeran Lee

    • University of Texas at Austin
    • Microelectronics Research Center, Department of Electrical and Computer Engineering, The University of Texas at Austin, Austin, Texas 78758, USA

  • Yimeng Wang

    • Microelectronics Research Center, Department of Electrical and Computer Engineering, The University of Texas at Austin, Austin, Texas 78758, USA

  • Kenneth Alexander Lin

    • University of Texas at Austin
    • Microelectronics Research Center, Department of Electrical and Computer Engineering, The University of Texas at Austin, Austin, Texas 78758, USA

  • Keiji Ueno

    • Department of Chemistry, Graduate School of Science and Engineering, Saitama University, Saitama 338-8570, Japan

  • Kenji Watanabe

    • National Institute for Materials Science
    • Research Center for Functional Materials, National Institute of Materials Science, 1-1 Namiki Tsukuba, Ibaraki 305-0044, Japan

  • Takashi Taniguchi

    • National Institute for Materials Science
    • Research Center for Materials Nanoarchitectonics, National Institute for Materials Science
    • International Center for Materials Nanoarchitectonics, National Institute of Materials Science, 1-1 Namiki Tsukuba, Ibaraki 305-0044, Japan
    • Research Center for Functional Materials, National Institute of Materials Science, 1-1 Namiki Tsukuba, Ibaraki 305-0044, Japan

  • Emanuel Tutuc

    • University of Texas at Austin
    • Microelectronics Research Center, Department of Electrical and Computer Engineering, The University of Texas at Austin, Austin, Texas 78758, USA