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Purpose. Investigation of the joint manifestation of the effects of anisotropic signal propagation, coupling, and nonlinear power dependence of the medium parameters in a lattice of laterally and vertically coupled spin-wave (SW) microwaveguides. Consideration of the case of the influence of the rotation of the magnetization angle and the change of the lateral gap between microwaveguides located on the same substrate on the transverse profile of the spin-wave beam and the spatial localization of the SW amplitude. Methods. The method of micromagnetic modeling based on the numerical solution of the Landau–Lifshitz–Hilbert equation shows the possibility of controlling the direction of propagation of SW in an ensemble of laterally and vertically coupled iron yttrium garnet (YIG) microwaveguides by changing the magnetization angle. By the method of numerical integration of the system of coupled discrete nonlinear Schrodinger equations, the possibility of changing the transverse profile of the spin-wave beam by changing the level of the initial signal amplitude is shown. Results. The spatial distributions of the components of the dynamic magnetization of the SW excited in two microwaveguides located on the same substrate obtained in micromagnetic simulations indicate a change in the character of localization of the SW power in the output sections of the microwaveguides. At variation of the lattice magnetization angle, a shift of the threshold power value is observed, at which a characteristic curbing of the transverse width of the spin-wave beam in the nonlinear mode appears. Conclusion. When excitation of surface magnetostatic SW in a lattice of laterally and vertically coupled microwaveguides, a transformation of the transverse profile of the wave is observed at a deviation of the magnetization angle of the structure by 15º , which is manifested in the change of the SW length and its localization in each of the microwaveguides. The combined effects of dipole coupling, gyrotropy, and nonlinearity of the medium make it possible to control the value of the threshold power of the SW, at which the mode of diffractionless propagation of the spin-wave beam is realized in a single layer of the structure.

Abstract. The purpose of research is to study of characteristics of the Fano resonance in a coupled system of nonlinear microwave-guides and resonators depending on geometric parameters of the systems, magnitude of the coupling between them, and the intensity of spin waves. Methods. Linear and nonlinear spin-wave excitations in lateral systems of irregular microwaveguides and resonators based on films of yttrium iron garnet are considered. Using micromagnetic simulation of spin-wave excitations and numerical integration of the coupled wave equation system, the transfer characteristics of the «microwaveguide – resonator» system and the Fano resonance parameters are calculated taking into account the cubic nonlinearity of magnetic media. Results. Based on the numerical integration of the system of equations of coupled waves that take into account the cubic nonlinearity of the magnetic media, theoretical studies have been carried out of the dependences of the transfer and phase characteristics of the «microwave-guide – resonator» system on the intensity of surface spin waves. Features of the demonstration of constructive and destructive interference of spin waves at Fano resonance are studied. Dependences of characteristics of the parameters of the Fano nonlinear resonance (asymmetry coefficient, resonance frequency shifts) on the intensity of spin-wave excitations are established. Conclusion. Results can be used to create spin-wave demultiplexers, power dividers and microwave couplers based on the lateral system of magnetic waveguides as a threshold element for neuromorphic networks, etc.

In this work, we present the results of investigations performed on hematite (α-Fe2O3), which is an antiferromagnet with weak ferromagnetism. Through the use of Brillouin light scattering spectroscopy, we studied experimentally the excitation of quasi-ferro- and antiferromagnetic modes in the bulk hematite. We investigated the influence of relative mechanical strains, ϵyy, on the frequencies of quasi-ferro- and antiferromagnetic modes. Also, we considered the angular dependence of the frequency of the quasi-ferromagnetic mode on the external magnetic field. Our results indicate that hematite is a suitable material for strain-controlled magnonic devices. [ABSTRACT FROM AUTHOR]

In this work, we present the results of investigations performed on hematite (α-Fe2O3), which is an antiferromagnet with weak ferromagnetism. Through the use of Brillouin light scattering spectroscopy, we studied experimentally the excitation of quasi-ferro- and antiferromagnetic modes in the bulk hematite. We investigated the influence of relative mechanical strains, ϵyy, on the frequencies of quasi-ferro- and antiferromagnetic modes. Also, we considered the angular dependence of the frequency of the quasi-ferromagnetic mode on the external magnetic field. Our results indicate that hematite is a suitable material for strain-controlled magnonic devices. [ABSTRACT FROM AUTHOR]