S. E. Sheshukova

Multimode Propagation of Magnetostatic Waves in a Width-Modulated Yttrium-Iron-Garnet Waveguide

An irregular tapered ferrite waveguide with a periodically width-modulated region was investigated. By using space- and time-resolved Brillouin light scattering spectroscopy, we measured the features of the intermodal interaction of width modes and their scattering at the boundaries of the waveguide. Near the band-gap frequency region, the spatial pattern of the spin-waves depends on the mode interaction in the periodically width-modulated yttrium-iron-garnet waveguide. These experimental results are important for controlling spin-wave propagation in width-modulated magnetic structures for future spintronic devices.

Frequency selective tunable spin wave channeling in the magnonic network

Using the space-resolved Brillouin light scattering spectroscopy, we study the frequency and wavenumber selective spin-wave channeling. We demonstrate the frequency selective collimation of spin-wave in an array of magnonic waveguides, formed between the adjacent magnonic crystals on the surface of yttrium iron garnet film. We show the control over spin-wave propagation length by the orientation of an in-plane bias magnetic field. Fabricated array of magnonic crystal can be used as a magnonic platform for multidirectional frequency selective signal processing applications in magnonic networks.

Nonlinear spin wave coupling in adjacent magnonic crystals

We have experimentally studied the coupling of spin waves in the adjacent magnonic crystals. Space- and time-resolved Brillouin light-scattering spectroscopy is used to demonstrate the frequency and intensity dependent spin-wave energy exchange between the side-coupled magnonic crystals. The experiments and the numerical simulation of spin wave propagation in the coupled periodic structures show that the nonlinear phase shift of spin wave in the adjacent magnonic crystals leads to the nonlinear switching regime at the frequencies near the forbidden magnonic gap. The proposed side-coupled magnonic crystals represent a significant advance towards the all-magnonic signal processing in the integrated magnonic circuits.

Self-Generation of Chaotic Dissipative Soliton Trains in Active Ring Resonator With 1-D Magnonic Crystal

Self-generation of chaotic dissipative soliton trains was observed in an active ring resonator based on 1-D periodical ferromagnetic structure (1-D magnonic crystal) in a grooves grating form. The grooves were cut off on the surface of yttrium iron garnet film with the help of a scribing technique and placed perpendicularly to the magnetostatic surface wave (MSSW) propagation. The presence of three magnon decay processes of MSSW, a frequency filtration, and a passive synchronization of the spin-wave self-modulation frequencies caused the self-generation of chaotic dissipative soliton trains. Passive synchronization was realized at frequencies of the first band gap because of the presence of a saturable absorption of a microwave signal.

Brillouin light scattering study of transverse mode coupling in confined yttrium iron garnet/barium strontium titanate multiferroic

Using the space-resolved Brillouin light scattering spectroscopy we study the transformation of dynamic magnetization patterns in a bilayer multiferroic structure. We show that in the comparison with a single yttrium iron garnet (YIG) film magnetization distribution is transformed in the bilayer structure due to the coupling of waves propagating both in an YIG film (magnetic layer) and in a barium strontium titanate slab (ferroelectric layer). We present a simple electrodynamic model using the numerical finite element method to show the transformation of eigenmode spectrum of confined multiferroic. In particular, we demonstrate that the control over the dynamic magnetization and the transformation of spatial profiles of transverse modes in magnetic film of the bilayer structure can be performed by the tuning of the wavevectors of transverse modes. The studied confined multiferroic stripe can be utilized for fabrication of integrated dual tunable functional devices for magnonic applications.

Formation of gap solitons in a finite magnonic crystal

The specific features of transmission of microwave pulses through the bandgap of a magnonic crystal when three-magnon decay processes of magnetostatic waves are allowed have been experimentally investigated. It is shown that soliton-like pulses can be formed under these conditions. The experimental data are compared with the results of numerical simulation.

Investigation of self-action effects of magnetostatic waves in ferromagnetic structures in terms of the system of Schrödinger equations with coherent or incoherent coupling

The effect of coupling on the nonlinear dynamics of magnetostatic wave pulses in layered ferromagnetic structures consisting of two ferromagnetic films has been investigated using the numerical solution to the systems of coherent and incoherent nonlinear Schrödinger equations. The conditions of formation and the possibility of controlling such effects as nonlinear beats, instability of fast solitons, trapping, and tracking have been discussed. The main features of these effects have been analyzed and the applicability of coupled structures to control the formation of nonlinear pulses of magnetostatic waves has been considered.

Nonlinear Magnetostatic Wave Propagation through One Dimensional Finite Magnonic Crystals

A model describing the propagation of surface magnetostatic waves in the one-dimensional finite length magnonic crystal (MC) with losses was constructed. The features of microwave pulse passing through the band gap of MC were investigated experimentally. The conditions of soliton-like pulse formation were defined experimentally and by numerical simulation.

Coupled spin waves in magnetic waveguides induced by elastic deformations in YIG–piezoelectric structures

The numerical simulation and Brillouin spectroscopy measurement have demonstrated the possibility of controlling the properties of coupled spin waves propagating in a transversely limited layered YIG–piezoelectric structure. It has been shown that an electric field applied to the piezoelectric layer induces an inhomogeneous distribution of an internal magnetic field in the ferromagnetic layer, which results in the formation of waveguide channels for spin magnetostatic waves. In this case, the properties of coupled spin waves can be efficiently controlled by varying the magnetization angle of the structure. The results demonstrate the possibility of integration of straintronics and magnonics to fabricate electric- and magnetic-field-controlled power splitters, multiplexers, and microwave couplers.

Spatial dynamics of hybrid electromagnetic spin waves in a lateral multiferroic microwaveguide

Regimes of the formation of spatial structures at the propagation of hybrid electromagnetic spin waves in a system of laterally coupled multiferroics, which consist of parallel ferromagnetic microwaveguides with a ferroelectric layer, are studied experimentally and theoretically. Brillouin spectroscopy measurements at frequencies near the ferromagnetic resonance by the method of selection of mode patterns reveal a sharp increase in the spatial scales of transfer of power between microwaveguides. The calculations of the characteristics of propagation of electromagnetic spin wave in a lateral multiferroic structure with a finite width show that energy exchange between films is due to the features of intermodal coupling between waves. Higher transverse modes and electric-field-induced transformation of spectra of the electromagnetic spin waves in the adjacent multiferroics are studied experimentally and numerically.