Magnetostatic modes in metamagnetic superlattices

A detailed analysis of the spin wave modes propagating in magnetic superlattices made up of two metamagnetic materials is carried out in the magnetostatic regime, for the antiferromagnetic phase. Our model takes into account the presence of an external applied magnetic field, which is perpendicular to the interfaces of the superlattice, as well as the crystalline anisotropic contribution to the inner magnetic field. The magnetostatic bulk and surface modes are obtained by using the transfer matrix technique. The metamagnetic material considered here is FeBr2, however, our results can be extended to other materials. Our numerical results show the presence of a striking behavior of these modes, for small frequencies of the energy spectra. The results reported here can be experimentally observed by light scattering techniques.