Spin excitations in the multiferroic skyrmion host GaV<sub>4</sub>S<sub>8</sub>

ORAL

Abstract

In GaV4S8, the interplay of spin, charge, and orbital degrees of freedom results in a complex phase diagram that includes cycloidal, ferromagnetic, ferroelectric, orbitally ordered, and skyrmion phases. To provide insight into the interactions rendering this complex phase diagram, the spin excitations in GaV4S8 are studied using inelastic neutron scattering measurements of polycrystalline and single crystalline samples. The characteristic features of spin waves propagating along the high symmetry directions (110) and (001) are described. A Heisenberg spin model with competing symmetric and asymmetric exchange (DM) interactions explain the experimental data. Simulation shows ferromagnetic inter-tetrahedral couplings with J= -0.70(3) meV. The modeling further indicates that the DM interactions are around 15% of the nearest neighbor exchange interactions. The finding of the interaction parameters in GaV4S8 provides an important information about the magnetic ground state in GaV4S8.

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Presenters

  • Ganesh Pokharel

    • California NanoSystems Institute, University of California, Santa Barbara

Authors

  • Ganesh Pokharel

    • California NanoSystems Institute, University of California, Santa Barbara

  • Hasitha Suriya Arachchige

    • Department of Physics & Astronomy, University of Tennessee, Knoxville, TN 37996, USA
    • University of Tennessee - Knoxville
    • Department of Materials Science, The University of Tennessee

  • Georg Ehlers

    • Neutron Scattering Division, Oak Ridge National Laboratory
    • Oak Ridge National Lab
    • Oak Ridge National Laboratory

  • Seunghwan Do

    • Materials Science and Technology Division, Oak Ridge National Laboratory
    • Oak Ridge National Laboratory

  • Matthew Brandon Stone

    • Oak Ridge National Lab
    • Oak Ridge national lab
    • Quantum Condensed Matter Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
    • Neutron Scattering Division, Oak Ridge National Laboratory
    • Oak Ridge National Laboratory
    • Oakridge National Laboratory

  • Mark D Lumsden

    • Oak Ridge National Laboratory

  • Hao Zhang

    • University of Tennessee
    • Department of Physics and Astronomy, University of Tennessee
    • Department of Physics and astronomy, University of Tennessee
    • Department of Physics and Astronomy, University of Tennessee, Knoxville
    • Department of Materials Science, The University of Tennessee

  • Yiming Qiu

    • NIST Center for Neutron Research, National Institute of Standards and Technology
    • NIST Center for Neutron research, National Institute of Standards and Technology
    • NIST
    • National Institute of Standards and Technology

  • Randy Fishman

    • Oak Ridge National Lab
    • Oak Ridge National Laboratory

  • Stephen D Wilson

    • University of California, Santa Barbara
    • Materials Department, University of California, Santa Barbara
    • California NanoSystems Institute, University of California, Santa Barbara

  • David George Mandrus

    • Materials Science and Technology Division, Oak Ridge National Labratory
    • Materials Science and Engineering, University of Tennessee
    • Department of Materials Science and Engineering, University of Tennessee
    • University of Tennessee
    • Department of Materials Science and Engineering, University of Tennessee Knoxville
    • Department of Materials Science & Engineering, University of Tennessee, Knoxville, Tennessee 37996, USA
    • Oakridge National Laboratory
    • Materials Science and Engineering, University of Tennessee, Knoxville
    • Oak Ridge National Laboratory
    • University of Tennessee - Knoxville
    • Materials Science and Technology Division, Oak Ridge National Laboratory
    • Department of Physics, University of Tennessee Knoxville
    • Materials Science and Technology, Oak Ridge National Laboratory
    • Oak Ridge National Laboratory, Materials Science and Technology Division
    • Department of Materials Science, The University of Tennessee
    • University of Tennessee, Knoxville

  • Andrew Christianson

    • Oak Ridge National Lab
    • Materials Science & Technology Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
    • Oak Ridge National Laboratory