Effects of symmetry reduction on magnon band gaps in two-dimensional magnonic crystals

Effects of symmetry reduction on the magnon band gaps (MBGs) in two-dimensional (2D) magnonic crystals (MCs) were investigated by solving the Landau–Lifshitz equation with the plane wave method. The symmetry reduction is achieved by introducing additional scatterers into each unit cell or by reorienting noncircular scatterers. The numerical results show that the MBGs in a square lattice can be improved by introducing additional scatterers or rotating the square rods. In honeycomb and triangular lattices, the MBGs can be improved only by introducing additional scatterers, however, rotating the square rods is an invalid way to increase the MBGs. (paper)