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A series of magnon crystals appearing under ultrahigh magnetic fields in a kagomé antiferromagnet

ORAL

Abstract

Geometrical frustration and a high magnetic field are two key factors for realizing unconventional quantum states in magnetic materials. Specifically, conventional magnetic order can potentially be destroyed by competing interactions and may be replaced by an exotic state that is characterized in terms of quasiparticles called magnons, the density and chemical potential of which are controlled by the magnetic field. Here we show that a synthetic copper mineral, Cd-kapellasite, which comprises a kagomé lattice consisting of corner-sharing triangles of spin-1/2 Cu2+ ions, exhibits an unprecedented series of fractional magnetization plateaus in ultrahigh magnetic fields of up to 160 T. We propose that these quantum states can be interpreted as crystallizations of emergent magnons localized on the hexagon of the kagomé lattice. [1] Okuma, R., et al. Nature communications 10.1 (2019): 1-7.

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Presenters

  • Ryutaro Okuma

    Department of Physics, University of Oxford

Authors

  • Ryutaro Okuma

    Department of Physics, University of Oxford

  • Daisuke Nakamura

    Institute for Solid State Physics, University of Tokyo

  • Tsuyoshi Okubo

    Institute for Solid State Physics, University of Tokyo, The University of Tokyo

  • Atsushi Miyake

    Institute for Solid State Physics, University of Tokyo, ISSP, University of Tokyo, ISSP, The University of Tokyo

  • Akira Matsuo

    Institute for Solid State Physics, University of Tokyo

  • Koichi Kindo

    University of Tokyo, Institute for Solid State Physics, University of Tokyo

  • Masashi Tokunaga

    Institute for Solid State Physics, University of Tokyo, ISSP, University of Tokyo, ISSP, The University of Tokyo, Univ of Tokyo

  • Naoki Kawashima

    Univ of Tokyo, Institute for Solid State Physics, University of Tokyo

  • Shojiro Takeyama takeyama@issp.u-tokyo.ac.jp

    Institute for Solid State Physics, University of Tokyo

  • Zenji Hiroi

    Institute for Solid State Physics, University of Tokyo