Through computer simulations of a microscopic model for a skyrmion crystal, theoreticians discovered an unexpectedly complex spin dynamics stabilized by Dzyaloshinskii-Moriya interaction. Understanding spin dynamics is of fundamental importance to create and manipulate exotic magnetic order, such as skyrmions, for spintronic applications.
Dynamical spin structure factor is a fundamental observable that can be detected by inelastic neutron scattering. In this work, using high-performance computers at ORNL, Monte-Carlo and Landau-Lifshitz simulations were carried out to analyze the time evolution of the complex magnetic structure. The skyrmion crystal arises as a compromise of competing tendencies. It has its own set of zero energy modes from momenta Q1,2,3 that characterize a triangular lattice of skyrmions. This study unveils complex spin-wave spectra due to the many zero modes. It will be possible to confirm the numerical results of this study by employing artificial superlattices of manganites and iridates. This work provides an opportunity to probe and understand complex spin dynamics using neutron scattering experiments.
