Resonant mode dynamics of two-dimensional ferromagnetic antidot lattices in the effective stripe limit

The resonant mode dynamics of two-dimensional permalloy antidot lattices in the nanometric range is studied theoretically in the effective stripe limit. The analysis is performed both according to a finite-difference micromagnetic approach, the dynamical matrix method, and by means of analytical calculations. The external magnetic field applied along the y-axis aligns the static magnetization along the same direction which induces the formation of “surface magnetic charges” on the border of the holes. The passage from a discontinuous to a continuous effective “surface magnetic charges” distribution in the effective stripe limit has a strong influence on the dynamics of the resonant mode of the system. Due to the large demagnetizing field it is shown via analytical calculations that the resonant mode of the effective one-dimensional stripe cannot exist above a given aspect ratio. The dynamical properties of the resonant mode dramatically change passing from a two-dimensional to a one-dimensional magnonic metamaterial.