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$_3$.

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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