  Lattice vibration modes are collective excitations in periodic arrays of
atoms or molecules. These modes determine novel transport properties in solid
crystals. Analogously, in periodical arrangements of magnetic vortex-state
disks, collective vortex motions have been predicted. Here, we experimentally
observe wave modes of collective vortex gyration in one-dimensional (1D) chains
of periodic disks using time-resolved scanning transmission x-ray microscopy.
The observed modes are interpreted based on micromagnetic simulation and
numerical calculation of coupled Thiele equations. Dispersion of the modes is
found to be strongly affected by both vortex polarization and chirality
ordering, as revealed by the explicit analytical form of 1D infinite chains. A
thorough understanding thereof is fundamental both for lattice vibrations and
vortex dynamics, which we demonstrate for 1D magnonic crystals. Such magnetic
disk arrays with vortex-state ordering, referred to as magnetic metastructure,
offer potential implementation into information processing devices.
