M. A. Morozova

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 dissipative solitons in magnonic quasicrystal active ring resonator

Self-generation of dissipative solitons in the magnonic quasicrystal (MQC) active ring resonator is studied theoretically and experimentally. The developed magnonic crystal has quasiperiodic Fibonacci type structure. Frequency selectivity of the MQC together with the parametric three-wave decay of magnetostatic surface spin wave (MSSW) leads to the dissipative soliton self-generation. The transfer matrix method is used to describe MQC transmission responses. Besides, the model of MQC active ring resonator is suggested. The model includes three coupled differential equations describing the parametric decay of MSSW and two differential equations of linear oscillators describing the frequency selectivity of MQC. Numerical simulation results of dissipative soliton self-generation are in a fair agreement with experimental data.

Magnonic Bandgap Control in Coupled Magnonic Crystals

The periodic structure in the form of two coupled magnonic crystals (MCs) was considered for the first time. It was shown that the variation of coupling allows to control effectively the characteristics of the bandgaps in the spectrum of magnetostatic spin waves. Main features of formation of the bandgaps were investigated in the basis of theoretical and experimental results. The comparison with a periodic structure in the form of a single MC was provided. The possibility of formation of two frequency bandgaps and shift of the frequency bandgaps depending on coupling was demonstrated in the frequency region of the first Bragg resonance. It was shown that the control of bandgaps in such structure gives additional opportunities to create microwave filters and phase shifters with desired characteristics.

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.

Tunable band gaps in a layered structure magnonic crystal-ferroelectric

A dispersion relation for a hybrid electromagnetic-spin wave in a layered structure magnonic crystal-ferroelectric has been derived. The main distinctions of the band gaps in this structure from those in a single magnonic crystal have been determined. It is shown that the characteristics of these zones can be tuning by the electric field.

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.

Tuning the bandgaps in a magnonic crystal–ferroelectric–magnonic crystal layered structure

A dispersion relation has been obtained for the hybrid electromagnetic spin wave in a magnonic crystal–ferroelectric–magnonic crystal layered structure. The mechanisms of the bandgap formation in this structure have been revealed, and the ability to double tune bandgap characteristics by means of the electric and magnetic fields has been shown.

Numerical modeling of wave processes in coupled magnonic crystals with periods shifted relative to each other

A calculation model has been developed to describe the propagation of magnetostatic waves in a periodic structure consisting of two one-dimensional magnonic crystals, the periods of which are shifted relative to each other in the wave propagation direction. It is shown that, depending on the shift between the magnonic crystals, up to three bandgaps can be formed in this structure in the first Bragg resonance.

Band gap formation and control in coupled periodic ferromagnetic structures

We demonstrate theoretically and experimentally the formation of additional bandgaps in the spectrum of spin waves in coupled magnonic crystals. We present the analytical model, which reveals the mechanism of bandgaps formation in coupled structures. In particular, the formation of one, two, or three bandgaps in the region of the first Bragg resonance is demonstrated and control of its characteristics by the variation of the complex coupling coefficient between magnonic crystals is shown. The spatially-resolved Brillouin light scattering spectroscopy and microwave measurements demonstrate the bandgap splitting in the spin-wave spectrum. The main advantage of proposed coupled structure, as compared to the conventional magnonic crystal, is the tunability of multiple bandgaps in the spin-wave spectrum, which enables potential applications in the frequency selective magnonic devices.

Propagation of nonlinear pulses of magnetostatic waves in coupled magnonic crystals

A periodic structure in the form of two coupled magnonic crystals in which the coupling allows effective control of nonlinear effects during propagation of magnetostatic waves is examined. The main specific features of the nonlinear effects are revealed in comparison with the periodic structure in the form of one magnonic crystal. The ability of the nonlinear coupler to suppress high- or lower-power signals for the functional processing of microwave-frequency signals is demonstrated.