Collective magnetic skyrmion gyrotropic modes in a dot chain

We investigate the collective gyrotropicmodes in a linear chain of ferromagnetic nanodots in a skyrmionmagnetization state. Individual skyrmions in the dots (with thickness about of 1 nmand radius about of 100 nm) are assumed to be stabilized by interplay of isotropic exchange and Dzyaloshinskii-Moriya exchange interactions,magnetic anisotropy andmagnetostatic interactions. We consider the dipolar and quadrupolar interactions betweenmoving skyrmions in the dots as prevailingmechanism responsible for dynamic interdotmagnetostatic coupling. The frequency dispersion relations of the collective skyrmion gyrotropic excitations are calculated for Bloch andNeel skyrmion configurations and related differences in the frequencies are discussed. The accounting of magnetostatic interactions between the skyrmions removes phase degeneracy of the gyrotropic frequency existing for isolated skyrmions and allows distinguishing the Bloch andNeel skyrmionic configurations by their dynamic response. The interdotmagnetostatic coupling and frequency bandwidth aremaximal for the large-radius Bloch skyrmions in the relatively thick dots.