Weyl orbit quantum Hall states observed in Dirac semimetal Cd<sub>3</sub>As<sub>2</sub> thin films

ORAL

Abstract

Topologically protected surface states in topological materials provide access to various unconventional transport phenomena. One example in gapless topological semimetals is the unique interplay between bulk and surface Fermi-arc states resulting in an exotic magnetic orbit (Weyl orbit). The Weyl orbit weaves together two spatially-separated Fermi-arc states across the bulk state under the field, allowing the appearance of two-dimensional (2D) quantized conduction even in a 3D system. Here, we report the observation of quantum Hall (QH) states in Dirac semimetal Cd3As2 thin films. By controlling Fermi level and band topology of the 3D bulk state with electrostatic gating and chemical-doping-induced topological phase transition, we clarify that the quantized conduction emerges originating from the Weyl orbit. In particular, the successive scan from bulk-dominant conduction to Weyl orbit QH effect, reveals that the emergence of the QH states depends on the bulk Landau level occupation and the induced asymmetry between the film surfaces.

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Presenters

  • Shinichi Nishihaya

    • Department of Applied Physics and Quantum-Phase Electronics Center (QPEC), the University of Tokyo
    • Department of Applied Physics and Quantum-Phase Electronics Center (QPEC), Univ. of Tokyo, Tokyo, Japan.

Authors

  • Shinichi Nishihaya

    • Department of Applied Physics and Quantum-Phase Electronics Center (QPEC), the University of Tokyo
    • Department of Applied Physics and Quantum-Phase Electronics Center (QPEC), Univ. of Tokyo, Tokyo, Japan.

  • Masaki Uchida

    • University of Tokyo
    • Department of Applied Physics and Quantum-Phase Electronics Center (QPEC), the University of Tokyo
    • Department of Applied Physics and Quantum-Phase Electronics Center (QPEC), Univ. of Tokyo, Tokyo, Japan.

  • Yusuke Nakazawa

    • Department of Applied Physics and Quantum-Phase Electronics Center (QPEC), the University of Tokyo
    • Department of Applied Physics and Quantum-Phase Electronics Center (QPEC), Univ. of Tokyo, Tokyo, Japan.

  • Ryosuke Kurihara

    • Institute of Solid State Physics (ISSP), Univ. of Tokyo, Kashiwa, Japan.

  • Kazuto Akiba

    • Okayama University
    • University of Tokyo
    • Institute of Solid State Physics (ISSP), Univ. of Tokyo, Kashiwa, Japan.

  • Markus Kriener

    • RIKEN Center for Emergent Matter Science (CEMS)
    • RIKEN Center for Emergent Matter Science (CEMS), Wako, Japan.

  • Atsushi Miyake

    • University of Tokyo
    • Institute of Solid State Physics (ISSP), Univ. of Tokyo, Kashiwa, Japan.

  • Yasujiro Taguchi

    • RIKEN Center for Emergent Matter Science (CEMS)
    • RIKEN Center for Emergent Matter Science
    • RIKEN Center for Emergent Matter Science (CEMS), Wako, Japan
    • Center for Emergent Matter Science (CEMS), RIKEN
    • RIKEN Center for Emergent Matter Science (CEMS), Wako, Japan.

  • Masashi Tokunaga

    • University of Tokyo
    • Institute of Solid State Physics (ISSP), Univ. of Tokyo, Kashiwa, Japan.

  • Masashi Kawasaki

    • The University of Tokyo
    • Department of Applied Physics and Quantum-Phase Electronics Center (QPEC), The University of Tokyo, Tokyo 113-8656, Japan
    • University of Tokyo
    • Applied Physics and QPEC, University of Tokyo
    • Department of applied physics, The University of Tokyo
    • Department of Applied Physics and Quantum-Phase Electronics Center (QPEC), the University of Tokyo
    • Department of Applied Physics and Quantum-Phase Electronics Center (QPEC), Univ. of Tokyo, Tokyo, Japan.