Asymmetric splitting of the antiferromagnetic resonance in multiferroic hexagonal HoMnO<sub>3</sub>

ORAL

Abstract

The high precision time domain terahertz spectroscopy has uncovered exceptionally strong and unconventional Ho-Mn spin interactions in hexagonal HoMnO3, manifesting as the mysterious asymmetrical splitting of antiferromagnetic resonance modes under weak external magnetic field along c-axis. The asymmetry indicates substantially different g-factors for the high and low energy branches of this excitation. To understand this, we studied the spin excitations on the Mn sublattice, focusing on the interaction between Mn ions and their nearest neighbor Ho layers. We propose a scenario including the simultaneous presence of Dzyaloshinskii-Moriya interaction between Mn ions and 2a Ho ions, and a quartic term possibly originating from high-order interaction. The significant renormalization of g-factors observed near the Ho ordering temperature is also explained.

*Research at JHU was funded by the U.S. Department of Energy, Office of Basic Energy Sciences, Division of Materials Sciences and Engineering through Grant No. DE-FG02-08ER46544. Work at Rutgers was supported by the DOE under Grant No. DOE: DEFG02-07ER46382. NJL acknowledges additional support through the

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Presenters

  • Yi Luo

    • Department of Physics and Astronomy, Johns Hopkins Unversity

Authors

  • Nicholas Laurita

    • Department of Physics and Astronomy, Johns Hopkins Unversity
    • Johns Hopkins Univ
    • Johns Hopkins University
    • Institute For Quantum Information and Matter, California Institute of Technology

  • Yi Luo

    • Department of Physics and Astronomy, Johns Hopkins Unversity

  • Rongwei Hu

    • Department of Physics and Astronomy, Rutgers University

  • Meixia Wu

    • Department of Physics and Astronomy, Rutgers University

  • Sang-Wook Cheong

    • Rutgers University
    • Department of Physics and Astronomy, Rutgers University
    • Department of Physics and Astronomy, Rutgers, The State University of New Jersey
    • Physics, Rutgers University
    • Physics and Astronomy, Rutgers University
    • Rutgers Center for Emergent Materials and Department of Physics and Astronomy, Rutgers University
    • Physics and Astronomy, Rutgers Univ.
    • Rutgers Univ
    • Physics, Rutgers Univesity
    • Department of Physics, Rutgers University
    • Physics and Astronomy, Rutgers Center for Emergent Materials
    • Department of Physics & Astronomy , Rutgers University

  • Oleg Tchernyshyov

    • Johns Hopkins Univ
    • Department of Physics and Astronomy, Johns Hopkins Unversity
    • Physics and Astronomy, Johns Hopkins Univ
    • Henry A. Rowland Department of Physics & Astronomy, Johns Hopkins University
    • Department of Physics and Astronomy, Johns Hopkins University

  • Peter Armitage

    • Department of Physics and Astronomy, The Johns Hopkins University
    • Department of Physics and Astronomy, Johns Hopkins Unversity
    • Johns Hopkins University
    • Johns Hopkins Univ
    • Institute for Quantum Matter, Johns Hopkins University
    • The Johns Hopkins University