Surface Spin Waves in a Two-Layer Ferromagnetic Structure

摘要

The spectrum of surface spin waves (SSWs) in a tangentially magnetized two-layer structure with the interlayer exchange and a normal single-axis surface anisotropy of the easiest-magnetization-axis type is investigated numerically. It is shown that the number of branches of the SSW spectrum localized near the layer interface is determined by the relation between the parameters of the interlayer exchange and surface anisotropy on the layer interfaces. In structures comprising identical layers with double-side-fixed spins, a resonance interaction of SSWs both with each other and with bulk spin-wave modes of the structure may occur. For the structures with the parameter distribution, which is asymmetric with respect to the interface, a change in the direction of the normal to the surface supporting SSWs or to the surface along which SSWs propagate at an angle to the tangent magnetic field changes the SSW dispersion law (the effect of nonreciprocity).