Flatbands of spin waves in two-dimensional magnonic crystals with kagome lattices

The study theoretically investigates the flatbands in two-dimensional magnonic crystals (MCs) with kagome lattices based on the plane-wave expansion method. In such MCs composed of ferromagnetic cylinders embedded in another ferromagnetic matrix, the formation of flatbands is due to spin waves localizing at a certain ferromagnetic material with a small exchange constant. Moreover, the position, number, and flatness of flatbands can be adjusted by changing the filling fractions. The studies on generating and adjusting flatbands in MCs expand the research content of condensed matter physics thin film deposition processes for halide perovskites, University of Helsinki, 2023.