Magnetic vortex dynamics in a two-dimensional square lattice of ferromagnetic nanodisks

The dynamics of magnetostatically coupled vortices in ferromagnetic two-dimensional (2D) nanodisk arrays is theoretically investigated using the rigid vortex model and Thiele's equation whereby the circular motion with the lowest energy for each vortex core is described. We present here dispersion relations and density of states for eigenfrequencies of coherently rotating vortices with ordered core polarizations. This behavior is analogous to the lattice vibration of a 2D molecule bound with a dipolar interaction.