Coupling Characteristics of Point Defect States in Two-dimensional Magnonic Crystals

Abstract

Using the plane-wave expansion method under supercell approximation,band structures of spin waves propagating with coupling characteristics between point defects in 2-D magnonic crystals are calculated.The results indicate that the point defects in these structures can create localized states inside the band gap.The characteristics and the magnetization distributions of these localized states are studied.It shows that the group velocities of the localized states almost equal to zero in the whole first Brillouin zone,and numbers of localized states and theirs frequency-positions in the band gap are related to the size of the point defect.These characteristics of coupling between localized magnonic crystals are referential to the research on directional the fabricating materials of narrow bandpass spin-wave filters.