Magnetoelectric spectroscopy of spin excitations in LiCoPO<sub>4</sub>

ORAL

Abstract

In this work [V. Kocsis et al., PRB100, 155124 (2019)] we study optical magnetoelectric (ME) effect using optical directional anisotropy as measured by the THz absorption spectroscopy of spin resonances in LiCoPO4. The antiferromagnetic domains are selected by ME poling and their population is measured by directional anisotropy [V. Kocsis et al.PRL121, 057601 (2018)]. Here we demonstrate that the directional anispotropy can also be used to investigate the form and the spectral dependence of the ME susceptibility tensor and hence to identify different spin-multipolar orders responsible for the ME effect. From the spectrum of the directional anisotropy one can determine the static ME coupling via the ME susceptibility sum rule. We conclude, for the poling magnetic field direction along the local electric polarization, the observed ME spin resonances are responsible for the static ME effect and the symmetric part of the ME tensor with zero diagonal elements dominates over the antisymmetric components.

*Part of the work was supported by The Estonian Ministry of Education
and Research under Grant No. IUT23-03, and the
European Regional Development Fund project TK134.

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Presenters

  • Toomas Room

    • National Institute of Chemical Physics and Biophysics
    • National Institute of Chemical Physics and Biophysics, Estonia

Authors

  • Toomas Room

    • National Institute of Chemical Physics and Biophysics
    • National Institute of Chemical Physics and Biophysics, Estonia

  • Johan Viirok

    • National Institute of Chemical Physics and Biophysics
    • National Institute of Chemical Physics and Biophysics, Estonia

  • Laur Peedu

    • National Institute of Chemical Physics and Biophysics
    • National Institute of Chemical Physics and Biophysics, Estonia

  • Urmas Nagel

    • National Institute of Chemical Physics and Biophysics
    • National Institute of Chemical Physics and Biophysics, Estonia

  • Sandor Bordacs

    • Budapest University of Technology and Economics
    • Department of Physics, Budapest University of Technology and Economics and MTA-BME, Hungary
    • Department of Physics, Budapest University of Technology and Economics, Hungary

  • Istvan Kezsmarki

    • University of Augsburg
    • Experimental Physics 5, Center for Electronic Correlations and Magnetism, Institute of Physics, University of Augsburg, Germany
    • Experimental Physics V, Center for Electronic Correlations and Magnetism, Institute of Physics, University of Augsburg

  • Vilmos Kocsis

    • RIKEN
    • Center for Emergent Matter Science (CEMS), RIKEN, Japan
    • Department of Physics, Budapest University of Technology and Economics, Hungary
    • Leibniz Institute for Solid State and Materials Research Dresden
    • RIKEN CEMS

  • Yusuke Tokunaga

    • RIKEN
    • Center for Emergent Matter Science (CEMS), RIKEN, Japan
    • Department of Advanced Materials Science, University of Tokyo
    • Univ of Tokyo-Kashiwanoha

  • Yasujiro Taguchi

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

  • Yoshinori Tokura

    • RIKEN
    • Center for Emergent Matter Science (CEMS), RIKEN, Japan
    • CEMS, RIKEN
    • RIKEN CEMS and University of Tokyo
    • Center for Emergent Matter Science (CEMS), RIKEN
    • RIKEN CEMS
    • Department of Applied Physics, The University of Tokyo
    • The University of Tokyo
    • Center for Emergent Matter Science, RIKEN
    • RIKEN Center for Emergent Matter Science