Staggered magnetization and low-energy magnon dispersion in the multiferroic skyrmion host Cu2OSeO3

ORAL

Abstract

We present neutron diffraction and inelastic scattering of the insulating helimagnet, Cu$_2$OSeO$_3$ which provide evidence for staggered magnetization and elucidate the associated low-energy magnon spectrum. The modulation wavelength of approximately $\lambda \approx 50$ nm detected at antiferromagnetic Bragg points is of the same length scale as previously reported for the skyrmion lattice. This superstructure evidences the composite nature of the spin-$1$ tetrahedra that form the topological magnetic structure of the material. To understand the interplay of ferrimagnetism and long wavelength modulated magnetism, we have performed inelastic neutron scattering on a co-aligned sample of chemical vapor transport grown single crystals. We shall present the low-energy magnon dispersion and infer an effective spin Hamiltonian to account for the long-wavelength, low-energy magnetism of Cu$_2$OSeO$_3$.

*The work at IQM was supported by the U.S. Department of Energy, Office of Basic Energy Sciences, Division of Material Sciences and Engineering, under Grant No. DEFG02-08ER46544. GGM also acknowledges support from the NSF-GRFP Grant No. DGE-1232825.

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Authors

  • Guy G. Marcus

    • Institute for Quantum Matter and Jonhs Hopkins University
    • Johns Hopkins University

  • Benjamin Trump

    • Institute for Quantum Matter and Jonhs Hopkins University
    • Johns Hopkins University
    • Johns Hopkins Univ

  • Jonas Kindervater

    • Physik-Department, Technische Universit\"at M\"unchen, Garching, Germany
    • Institute for Quantum Matter and Jonhs Hopkins University

  • Lacy L. Jones

    • Quantum Condensed Matter Division, Oak Ridge National Laboratories

  • Matthew Stone

    • Oak Ridge NAtional Lab., TN, 37831
    • Quantum Condensed Matter Division, Oak Ridge National Laboratories
    • Quantum Condensed Matter Division, Oak Ridge National Laboratory
    • Oak Ridge National Laboratory
    • Spallation Neutron Source, Oak Ridge National Laboratory

  • Tyrel M. McQueen

    • Johns Hopkins Univ
    • Institute for Quantum Matter and Jonhs Hopkins University
    • Institute for Quantum Matter and Johns Hopkins University
    • Johns Hopkins University
    • Institute for Quantum Matter, Johns Hopkins University

  • Collin Broholm

    • Institute for Quantum Matter, Jonhs Hopkins University, and Quantum Condensed Matter Division, Oak Ridge National Laboratories
    • Johns Hopkins University
    • Institute for Quantum Matter and Johns Hopkins University
    • Johns Hopkins University, Institute for Quantum Matter
    • Johns Hopkins Univ