Coupling characteristics of point defects modes in two-dimensional magnonic crystals

The coupling characteristics of two-point defects modes and multi-point defects modes in two-dimensional magnonic crystals composed of Fe square rods/EuO square lattices are studied based on the plane-wave expansion method under supercell approximation. The results show that the coupling degree of these defect modes depends not only on the distance between defect bodies, but also on the arrangement direction of point defects. The phase of precession of defect modes' magnetization distributions varies as the distance between the defects changes. These magnonic crystals with multi-point defects can be used as the fabricating materials of the directional spin-wave filters or the narrow band spin-wave waveguides. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4766907]