Half-integer quantized anomalous thermal Hall effect and topological Chern number in the Kitaev material α-RuCl<sub>3</sub>

ORAL

Abstract

Kitaev quantum spin liquid (QSL) displays the fractionalization of quantum spins into Majorana fermions. In magnetic fields, the emergence of Majorana edge current leads to a half-integer quantized thermal Hall conductance, which has recently been reported for the two-dimensional honeycomb material α-RuCl3 [1]. We find that the thermal Hall plateau appears even for a magnetic field with no out-of-plane components, which is in stark contrast to the conventional electronic Hall effect that requires a perpendicular magnetic field. Field-angular variation of the topological Chern number determined by the sign of the quantized thermal Hall conductance is consistent with that predicted for the pure Kitaev QSL. These results provide evidence that the Kitaev interaction is of prime importance for realizing the non-Abelian topological order in α-RuCl3 [2].

[1] Y. Kasahara et al., Nature 559, 227-231 (2018).
[2] T. Yokoi et al., arXiv:2001.01899.

*This work was supported by Grants-in-Aid for Scientific Research (KAKENHI) from JSPS and JST CREST (JP-MJCR18T2).

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Presenters

  • Yuichi Kasahara

    • Department of Physics, Kyoto University
    • Kyoto Univ
    • Physics, Kyoto University
    • Department of physics, Kyoto University

Authors

  • Yuichi Kasahara

    • Department of Physics, Kyoto University
    • Kyoto Univ
    • Physics, Kyoto University
    • Department of physics, Kyoto University

  • Taichi Yokoi

    • Department of Physics, Kyoto University

  • Sixiao Ma

    • Department of Physics, Kyoto University

  • Shigeru Kasahara

    • Department of Physics, Kyoto University
    • Kyoto Univ
    • Department of physics, Kyoto University

  • Takasada Shibauchi

    • Department of Advanced Material Science, University of Tokyo
    • Department of Advanced Materials Science, University of Tokyo
    • Department of Advanced Materials Science, The University of Tokyo
    • Dept. Adv. Mat. Sci., Univ. Tokyo
    • Univ of Tokyo-Kashiwanoha
    • Department of Advanced Materials Science, the University of Tokyo

  • Nobuyuki Kurita

    • Department of Physics, Tokyo Institute of Technology

  • Hidekazu Tanaka

    • Department of Physics, Tokyo Institute of Technology

  • Joji Nasu

    • Department of Physics, Yokohama National University
    • Yokohama National University

  • Yukitoshi Motome

    • Department of Applied Physics, University of Tokyo
    • Univ of Tokyo
    • Department of Applied Physics, The University of Tokyo

  • Ciaran Hickey

    • Institute for Theoretical Physics, University of Cologne

  • Simon Trebst

    • Institute for Theoretical Physics, University of Cologne
    • University of Cologne
    • Physics, University of Cologne

  • Yuji Matsuda

    • Department of Physics, Kyoto University
    • Kyoto Univ
    • Physics, Kyoto University
    • Department of physics, Kyoto University