Direct measurement of terahertz conductivity in a gated monolayer semiconductor

ORAL

Abstract

Two-dimensional semiconductors and their moiré superlattices have emerged as important platforms for investigating correlated electrons. However, many key properties of these systems, such as the frequency-dependent conductivity, remain experimentally inaccessible because of the mesoscopic sample size. Here we report a technique to directly measure the complex conductivity of electrostatically gated two-dimensional semiconductors in the terahertz frequency range. Applying this technique to a WSe2 monolayer encapsulated in hBN, we observe clear Drude-like response between 0.1 and 1 THz, in a density range challenging to access even in DC transport. Our work opens a new avenue for studying tunable van der Waals heterostructures using terahertz spectroscopy.

*The THz measurement was supported by the NSF award no. 2311205. The device fabrication was supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, Materials Sciences and Engineering Division under contract no. DE-AC02-05-CH11231 (van der Waals heterostructures program, KCWF16).

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Publication: arXiv:2409.17633

Presenters

  • Sudi Chen

    • University of California, Berkeley

Authors

  • Sudi Chen

    • University of California, Berkeley

  • Qixin Feng

    • University of California, Berkeley

  • Wenyu Zhao

    • University of California, Berkeley

  • Ruishi Qi

    • University of California, Berkeley

  • Zuocheng Zhang

    • University of California, Berkeley

  • Dishan Abeysinghe

    • University of California, Berkeley

  • Can Uzundal

    • University of California, Berkeley

  • Jingxu Xie

    • Lawrence Berkeley National Laboratory

  • 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

  • feng wang

    • University of California, Berkeley