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.

*R.O. achknowledges support from the European Research Council under the European Union Horizon 2020 Research and Innovation Programme via Grant Agreement 788814-EQFT and the Materials Education Program for the Future Leaders in Research, Industry, and Technology (MERIT) under the Ministry of Education, Culture, Sports, Science, and Technology of Japan (MEXT).

–

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