Confined spin-wave characteristics in magnetic nanowire ensembles approaching the ultrathin regime

We present a comprehensive study on the high-frequency magnetization dynamics of homogeneously patterned ultrathin magnetic nanowire arrays. The backward volume magnetostatic spin-wave (BVMSW) and Damon-Eshbach (DE) configurations are studied along with the intermediate transition states to understand the edge mode's evolution in depth. We find at the sub-10-nm ultrathin regime the dynamics are heavily influenced by geometrical parameters such as magnetic layer thickness (tFM), demagnetization factors, and interfaces. Critical entities such as field separation delta H between uniform to edge mode increase linearly with 1/tFM, while the edge saturation field Hedge sat increase monotonically with increasing tFM, revealing excellent agreement between findings from experimental and micromagnetic simulations. The dynamics are less sensitive to the width of the nanowire but very sensitive to the adjacent material or the interface of the ferromagnet, especially at the ultrathin limits.