Spectrum of elementary excitations of a single domain wall in garnet films with in-plane magnetization

Epitaxial garnet films with in-plane magnetization are studied by microwave technique. Resonances related to different branches of domain wall excitations are observed : a low-frequency Goldstone branch of translational wall vibrations in the MHz band and a high-frequency Gilinskii branch in the GHz band. A strong coupling between neighbouring domain walls is observed, if their distance becomes comparable to the wall thichkness. In this case each resonance is split into two coupled rasonant modes, their frequencies being larger at smaller wall distances. Spin wave excitations of a single wall are analyzed by numerical solution of Landau-Lifshitz and magnetostatic equations for the case of a bulk orthorhombic ferromagnetic material. Unidirectional Gilinskii branch and asymmetric Goldstone branch are shown to exist in the spectrum of the wall excitations for the case of the propagation direction perpendicular to the magnetization in domains. Unexpected wall excitation spectra are predicted at some values of the anisotropy parameters when the wall becomes unstable. Such spectrum shows a gap in the wave number and a loop in the dispersion of the Goldstone branch

Analysis of nonreciprocal light propagation in multimode imaging devices

We investigate a structure consisting of a magneto-optic multimode waveguide and two monomode waveguides serving as in- and outlets. The geometrical dimensions of the multimode waveguide can be adjusted such that the guided modes interfere constructively in forward direction and destructively for backward propagation. In this paper we present concepts for a circulator and two isolators based on multimode imaging

The anisotropy model on a compensated interface of cubic ferromagnet-antiferromagnet with structure Cu3Au (L12)

Abstract: Magnetoresistive memory (MRAM) is potentially capable to replace most of the various types of modern semiconductor memory. The key element of the MRAM cell is an antiferromagnetic layer with a FCC lattice that fixes the magnetization of the adjacent ferromagnetic layer. In this paper we study the mechanism of the appearance of the exchange anisotropy on the compensated interface of an antiferromagnet and a ferromagnet, there is constructed a multilayered micro-magnetic model of an antiferromagnet. It is shown that the direction of the anisotropy axis is determined by one of the eight states of the antiferromagnet. The traditional single-layer macro-spin model of an antiferromagnet gives incorrect results. There is proposed an effective two-layer model of an antiferromagnet with a 'heavy' inner layer.Note: Research direction:Mathematical modelling in actual problems of science and technic

Applications of magneto-optical waveguides in integrated optics: review

Magnetooptical garnets combine high Faraday rotation with low optical losses in the near infrared region where optical communication via glass ?ber is established. In this spectral range garnets are the only materials discussed to realize nonreciprocal devices as optical isolators and circulators. Although such devices are available as microoptical components, practical versions of their integrated counterparts are still lacking. Numerous concepts have been developed theoretically many of which are tested experimentally. This paper presents an overview of the state of the art of the applications of garnet films in integrated optics. Also the technique of combining garnets with semiconductor materials is shortly discussed