Electronic transport studies of ultrathin bismuth grown inside van der Waals materials

ORAL

Abstract

Bismuth exhibits a wide variety of topological electronic phenomena depending on its dimensionality. 3D bismuth sits at a transition between different topological phases, while 2D bismuth is predicted to be a room temperature 2D topological insulator. Studies of 2D and ultrathin bismuth are limited by irregular surfaces and substrate interactions in MBE. We present a new synthesis approach where ultrathin bismuth crystals are molded from the melt phase inside vdW materials under compression. This method consistently produces 5-30 nm thick bismuth crystals with atomically flat surfaces and single crystal domains up to 10 um in size. Cryogenic transport studies of the vdW-molded ultrathin bismuth exhibit metallic temperature dependence, as a result of the SOC-induced surface states conducting in parallel with the gapped bulk bands due to confinement effect. The residual resistance ratio is 10x larger than epitaxial-grown bismuth of similar thicknesses. Furthermore, magnetotransport shows gate-tunable quantum oscillations originating from the multi-pocket surface states. In my talk, I will present up-to-date transport data analysis including thickness-dependence and field effects on various ultrathin bismuth devices. We anticipate that the vdW-molding technique will be generalized for other soft materials and our research can cast new light on ultrathin bismuth studies.

*This talk is based upon work supported by the Air Force Office of Scientific Research under award number FA9550-21-1-0165. Additional support comes from the National Science Foundation (NSF) Materials Research Science and Engineering Center (MRSEC) program through the UC Irvine Center for Complex and Active Materials (DMR-2011967) Seed Program

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Presenters

  • Laisi Chen

    • University of California, Irvine

Authors

  • Laisi Chen

    • University of California, Irvine

  • Amy X Wu

    • University of California, Irvine

  • Naol Tulu

    • University of California, Irvine

  • Joshua Wang

    • University of California, Irvine

  • Adrian Juanson

    • California State University Long Beach

  • 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

  • Yinong Zhou

    • University of California, Irvine

  • Chaitanya A Gadre

    • University of California, Irvine

  • Marshall A Campbell

    • University of California, Irvine

  • Luis A Jauregui

    • University of California, Irvine

  • Xiaoqing Pan

    • University of California, Irvine

  • Ruqian Wu

    • University of California, Irvine

  • Javier Sanchez-Yamagishi

    • University of California, Irvine