Effective dynamic susceptibility of a one-dimensional array of ferromagnetic wires

In this paper the calculation of the effective dynamic susceptibility for a one-dimensional array of permalloy rectangular nanowires periodic along the in-plane x direction is presented. The external magnetic field is assumed aligned along the long side of the wires (y direction) and the in-plane Bloch wave vector is along the wires width (x direction). The calculation is performed by means of a finite-difference micromagnetic approach, the Lagrangian-based dynamical matrix method. It is shown that the excited spin-wave mode is always the quasi-uniform or fundamental mode of the spectrum. This spin excitation has a non-uniform amplitude along the wire width due to confinement with no nodal planes and can be regarded as the metamaterial wave of the one-dimensional periodic system.