ausblenden:
Schlagwörter:
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Zusammenfassung:
Complex low-temperature-ordered states in chiral magnets are typically
governed by a competition between multiple magnetic interactions. The
chiral-lattice multiferroic Cu2OSeO3 became the first insulating
helimagnetic material in which a long-range order of topologically
stable spin vortices known as skyrmions was established. Here we employ
state-of-the-art inelastic neutron scattering to comprehend the full
three-dimensional spin-excitation spectrum of Cu2OSeO3 over a broad
range of energies. Distinct types of high-and low-energy dispersive
magnon modes separated by an extensive energy gap are observed in
excellent agreement with the previously suggested microscopic theory
based on a model of entangled Cu-4 tetrahedra. The comparison of our
neutron spectroscopy data with model spin-dynamical calculations based
on these theoretical proposals enables an accurate quantitative
verification of the fundamental magnetic interactions in Cu2OSeO3 that
are essential for understanding its abundant low-temperature
magnetically ordered phases.
