Influence of spin wave attenuation on a ferromagnetic nanowire-based magnonic Bragg mirror

Abstract A theoretical study of classical spin waves propagating in axially magnetized, lossy ferromagnetic nanowires is considered, resulting in a model for a magnonic Bragg mirror based on an axially periodic arrangement of identical nanowire segments. While the system shows evidence of one-dimensional magnonic band gaps, with widths increasing as the inter-nanowire exchange coupling strength decreases, spin wave attenuation effects can be quite dramatic for magnetic damping constants within the range 0.001–0.1. In fact, calculated reflectance spectra for nanowire structures with a damping constant on the order of 0.01 exhibit relatively intense Bragg peaks only when the nanowire segment length is no more than an order of magnitude larger than the exchange length.