Vol 87, No 1 (2023)

The process of formation and propagation of vortex solitons in a tunnel-coupled waveguide with cubic nonlinearity in the case of anomalous dispersion is investigated by computer modeling methods. Obtaining stable solutions could be possible due to the introduction into the structure of an analogue of the spin-orbit coupling realized in binary Bose–Einstein condensates.

Optical properties of a composite structure consisting of two sequentially arranged three-layer metal-dielectric-metal structures (MDM-structures) are considered. It is shown that such a composite MDM-structure can perform second-order spatiotemporal differentiation with high quality at normal incidence. The obtained results can find application in creating systems for analog optical computing and optical information processing.

The mutual influence of solitons propagating along the axes of a two-dimensional graphene superlattice in mutually perpendicular directions has been studied. It is shown that due to the nonadditivity of the energy spectrum of the structure, the overlap region of solitons undergoes characteristic changes associated with the formation of pulses propagating along the fronts of interacting solitary waves.

The breather electric effect in a graphene superlattice has been studied in the collisionless approximation. When calculating the drag current density, an approximate solution in the form of a small-amplitude traveling breather of the nonlinear Klein–Gordon equation describing the propagation of nonlinear waves in a graphene superlattice is used. The breather travel time due to collisional dissipation is estimated.

A scheme of a specialized analog processor implementing a microwave photonics correlation receiver in the form of a matched filter for processing an ultra-wideband microwave signal is proposed. The operation of such a filter is numerically investigated, its characteristics are found (accuracy of determining the position of the maximum of the output signal, potential performance).

A transceiver has been designed for the digital generation of a multibeam radiation pattern in this work. The transceiver consists of a transmitter and receiver, both are integrated on a single printed circuit board. The transceiver provides the formation of multiple beams in the far field of the radiation zone. The experimental measurement of the multibeam radiation pattern of a phased antenna array with a digital pattern synthesis was carried out.

Single-particle energy spectra of one-dimensional metal-organic framework chain’s fragments were obtained with the density functional theory method. An effective resistance of an organic part of the polymer, coulomb energy and effective capacitance of a charge center were calculated. The number of conductive channels in an experimentally studied reservoir network based on the observed polymer chains was estimated.

Pulsed acoustic microscopy (100–200 MHz) was used to study layers of pyrolytic graphite on a glass substrate with a thickness comparable to wavelength of the probing sound. Mechanism of natural amplification of acoustic contrast in visualization process of such structures is shown. Images interpretation of the inhomogeneous structure of the layer-substrate contact is supported by a quantitative assessment of acoustic impedances.

The propagation of two-dimensional periodic capillary-gravitational waves in a viscous homogeneous liquid with a free surface in the frequency range from \(5 \cdot {{10}^{{ - 2}}}\) to \(5 \cdot {{10}^{4}}\) Hz is investigated. Dispersion relations are obtained, as well as expressions for phase and group velocities for surface waves in physically observable variables. It is shown that there is another class of solutions that is not observed in the ideal fluid model.

The heavy metal/ferromagnet type MgO/CoFeB/Ta structure with in-plane magnetization and high spin polarization was studied. We use the adiabatic harmonic Hall voltage method to study the effective damping coefficient and to estimate the values of the effective fields that arise in such structures under the action of a spin-polarized current.

Using the local Lyapunov exponents approach it was found that multistability near boundary of generalized synchronization can occur in systems with a complex attractor topology both in unidirectional and mutual coupling cases.

We studied physiological and behavioral characteristics of a person during prolonged solution of a cognitive task based on Sternberg paradigm. We found that evaluation of subjective fatigue and physiological characteristics such as blink duration and pupil size range of motion during the task solution are correlated to each other.

We present the results of the auroral hiss propagation modeling from the source region to the ground and its comparison with the observed results. We analyzed propagation conditions explaining locality of the auroral hiss illuminated area observed on the ground. It is shown that quasielectrostatic waves with random amplitudes, phases and wavenormals directions representing the auroral hiss propagating to the ground form two wave beams in the meridional plane. The scattering of these waves at altitudes of 800–1300 km can cause the observed locality of the illuminated area.

A method for determining the energy of a singlet quasibound pp-state in the d + ¹H → n + p + p reaction is considered. Procedures for obtaining experimental data on the measurement of the pp-scattering length and extracting of the proton-proton state energy from the experimental data using the χ² minimum method are presented.