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Vol 70, No 4 (2025)
Articles
К 70-летию со дня рождения Сергея Аполлоновича Никитова
Radiotehnika i èlektronika. 2025;70(4):289-291
289-291
ON THE 70th ANNIVERSARY OF S.A. NIKITOV
Spin waves in magnetic microstructures: magnon logic and information processing
Abstract
This paper presents a review of the current state of research in magnonics aimed at developing energy-efficient element base for information systems and technologies based on the effects of excitation, propagation and detection of spin waves in thin-film magnetic micro- and nanostructures. The progress achieved in the development of materials for spin waveguides, as well as in the methods of excitation, reception and control of spin wave propagation is discussed. Practical implementations of the effects of spin wave propagation in magnetic microstructures for constructing a number of logical keys, processing magnetic images, neuromorphic computing, ultra-high-frequency information processing devices and magnetic sensors, as well as problems that need to be solved for further development are considered.
Radiotehnika i èlektronika. 2025;70(4):292-331
292-331
Electroacoustic Shear Waves in the Hollow Structure of Two Piezoelectric
Abstract
The results of papers are presented in which dispersion properties of electroacoustic waves in the gap structure of two different piezoelectrics are considered. In particular, it is shown that in the presence of a difference of shear wave velocities in piezoelectrics there are no purely symmetric and antisymmetric modes, and the coefficients of the boundary localization of the shear wave will be significantly different. It is established that at a certain equal level of loss and gain (PT is a symmetrical structure) of two identical piezoelectrics of symmetry class 6, the symmetric and antisymmetric modes intersect. The intersection point defines an exceptional point of the PT-symmetric structure. Taking into account the unequal level of loss and gain in piezoelectrics results in either intersection, touching, or convergence of two modes at the point of their degeneracy (exceptional point) in the shear wave spectrum. As in the case of a purely PT-symmetric structure, the frequency dependence of the amplitude at an exceptional point of a quasi PT-symmetric structure (with a rather small difference in loss and gain levels) exhibits a very narrow peak, which opens up the possibility of creating hypersensitive sensors based on them.
Radiotehnika i èlektronika. 2025;70(4):332-347
332-347
Research on the creation of anticollision radio frequency identification tags on surface acoustic waves
Abstract
An overview of the results of twenty years of research on solving the problem of anticollision protection of radio frequency identification tags on surface acoustic waves is given. A comparison of different methods of anticollision protection is carried out. The results of solving this problem for an unlimited number of tags are presented.
Radiotehnika i èlektronika. 2025;70(4):348-354
348-354
Idealized passive elements of complex fractional order. Part 1. Classification
Abstract
The concept of an idealized passive element of complex fractional order γ = α + jβ, a synonym for which is an ideal complex fractal element (ICFE), is introduced. The corresponding basic and derived parameters of the ICFE are introduced. It is shown that the ICFE is a generalized two-pole passive element of fractal radio electronics, which generalizes the properties of not only all existing idealized passive two-pole elements, but also infinitely expands the capabilities of the modern element base. A classification of all existing two-pole passive idealized passive elements is given depending on the value of the complex fractional impedance index. The dimensions and physical meaning of these elements are determined depending on the values of α and β.
Radiotehnika i èlektronika. 2025;70(4):355-362
355-362
Phonon transport features in dielectrics with nanostructured inhomogeneities
Abstract
The peculiarities of heat capacity and phonon spectrum in single crystals of yttrium-rare earth aluminum garnets solid solutions Y3–xRexAl5O12 (Re-Ho;Er) prone to clustering are analyzed. It was shown that nanoscale inhomogeneities in single crystals of solid solutions can be responsible for the formation of additional local modes in heat capacity in the low-temperature region.
Radiotehnika i èlektronika. 2025;70(4):363-369
363-369
Detection of microwave radiation by a ferromagnetic/normal metal heterostructure in the near field of an antenna
Abstract
The operation of a spintronic detector in the near field of an antenna emitting a microwave signal at a frequency of 10 GHz has been investigated. The feasibility of using a detector based on a Lu₃Fe₅O₁₂/Pt heterostructure, operating due to the inverse spin Hall effect, has been studied. A comparison was made between the experimentally measured output voltage of the detector and theoretical calculations of the power distribution of the electromagnetic field, performed using COMSOL Multiphysics. The sensitivity of the detector was determined, and the dependence of the output signal on the distance to the radiation source was measured. The obtained results confirm the feasibility of using spintronic heterostructures in wireless data and energy transmission systems. The prospects for using the detector in wireless communication and data transmission systems operating in the near field of an antenna, such as RFID (Radio Frequency Identification) and NFC (Near Field Communication), are considered.
Radiotehnika i èlektronika. 2025;70(4):370-375
370-375
Nonlinear magnetization dynamics in Bose-Einstein condensation of magnons
Abstract
An equation for the dynamics of a Bose-Einstein condensate of magnons in a ferromagnetic film is presented, derived from quantum mechanical theory. The main interactions influencing the evolution of the condensed state are considered. An autonomous system of first-order differential equations describing the amplitude and phase of condensed magnons is obtained from the equation for their annihilation operator. The phase trajectories of such a system are investigated using the method of constructing phase portraits and determining the stability of stationary points.
Radiotehnika i èlektronika. 2025;70(4):376-383
376-383
New possibilities for using specialty optical fibers
Abstract
The results of the development and creation of various specialized optical fibers (SOF) for use in science and technology are presented. Methods of creating SOFs with Bragg structures recorded in the light-guiding core are described directly during the process of extracting SOF. Reflective signal sensors and single-frequency laser complexes were created on the basis of these sensors. Fiber-based refractive index meters for liquids were obtained using precise thinning of reflective claddings and nanocoatings. Ways of using multi-core SOFs and possibilities for creating end devices based on them have been shown.
Radiotehnika i èlektronika. 2025;70(4):384-395
384-395
Double negative media based on magnetic metamaterials and semiconductors for the microwave frequency range
Abstract
The results of theoretical study and MaxLLG program simulation of the ferromagnetic metamaterials with metallic (non-magnetic) inclusions, as well as the bigyrotropic media with the properties of a ferromagnetic semiconductor are presented. The possibility of obtaining the double negative media from such materials in that a backward electromagnetic wave exists at microwave frequencies is demonstrated.
Radiotehnika i èlektronika. 2025;70(4):396-404
396-404
Dispersion characteristics of spin waves in a nanoscale magnon crystal
Abstract
The paper presents the results of a study of the features of spin wave propagation in a magnon crystal based on a nanoscale ferromagnetic film with a periodic system of grooves on the surface. Micromagnetic modeling was performed in the MuMax3 environment. It is established that additional hybrid modes on the dispersion characteristic for a magnon crystal near each main width mode are formed. The ratio of ridge to groove widths affects the energy distribution between hybrid modes and the cutoff frequency of the main modes. The influence of the ridge/groove ratio on the formation of band gaps based on dispersion and amplitude-frequency characteristics is analyzed. It is shown that the most pronounced band gaps are observed for large ridge/groove width ratios. Also, an increase in the ridge/groove ratio and an increase in the groove depth leads to an increase in the number of orders of pronounced Bragg resonances.
Radiotehnika i èlektronika. 2025;70(4):405-411
405-411
Single-channel magnonic demultiplexer based on a transversely confined coupled waveguide and a Mach–Zehnder interferometer
Abstract
The propagation of spin waves in a system composed of a Mach–Zehnder interferometer (MZI) and a transversally confined waveguide based on yttrium iron garnet has been investigated. Micromagnetic simulations demonstrate the possibility of using the system as a single-channel demultiplexer for spin-wave signals. It is shown that the distance between the MZI and the transversally confined waveguide, as well as variations in the waveguide width, affect both the phase shift of the propagating signal and the coupling efficiency in the interaction region. The demultiplexing characteristics of the structure are presented, revealing its potential for spatial–frequency signal selection. The proposed coupled waveguide–MZI system provides a basis for the implementation of logic operations and may be employed in integrated circuits based on magnonic principles.
Radiotehnika i èlektronika. 2025;70(4):412-417
412-417
Dispersion and polarization characteristics of waveguide modes of exchange spin waves in epitaxial YIG films
Abstract
The properties of exchange spin waves (ESW) in epitaxial films of yttrium iron garnet (YIG) are investigated in this paper. A comprehensive analysis of the peculiarities of excitation, propagation, and interaction of ESW is carried out, taking into account their anisotropic properties. A methodology for calculating the dispersion and energy characteristics of waveguide modes of ESW for various directions of wave propagation in tangentially magnetized YIG films is proposed. It is established that the presence of both elliptical and linear polarization of precession waves leads to the deformation of the trajectory of the magnetization precession vector and a change in the orientation of the symmetry axes of the elliptical trajectory. Good agreement between the calculated and measured characteristics of ESW has been experimentally confirmed. The obtained results allow for the creation of new types of functional devices for information transmission, storage, and processing based on short-wavelength exchange spin waves.
Radiotehnika i èlektronika. 2025;70(4):418-426
418-426