Vol 87, No 2 (2023)

A computational scheme has been developed to determine the energies of neutral excitations in fractional states of the quantum Hall effect. The fractional states are brought into a general hierarchical system (Farey-number hierarchy structure). It is shown that in addition to the well-known hierarchy of fractional states (Laughlin–Jane), there are other ‘dark hierarchies’ of fractional quantum Hall effect that are not observed experimentally in the most highly mobile samples but can have a significant impact on the thermodynamics and spectral characteristics of fractional quantum Hall effect states. The connection of the ‘dark hierarchies’ of fractional quantum Hall effect with the existing experimental data is considered.

Characteristics of the silicon-based sub-THz plasmon detector were studied in a wide temperature range, down to the temperature of the liquid nitrogen. Temperature dependences of the detector sensitivity were obtained, and its noise characteristics were studied. The frequency dependence of the sensitivity in the frequency range 70–120 GHz was measured at room temperature, with the maximum of 25 V/W reached at the frequency of 96 GHz. The noise equivalent power of the detector under study was estimated assuming that the main source of noise was of Nyquist nature and varied from a value of 2 · 10^–10 W · Hz^–1/2 at room temperature down to 2 · 10^–11 W · Hz^–1/2 at temperature of the liquid nitrogen. Additionally, the volt-ampere characteristics of the sub-THz detector were investigated. It was found that the feature in the differential resistance and sensitivity as a function of the applied DC voltage emerges at the temperature of the liquid nitrogen.

Stimulated radiation with a high circular polarization degree in chiral semiconductor microcavities was studied in a wide temperature range. The kinetics of the spectra emission rearrangement in injection laser nanostructures during the action of a rectangular electric excitation pulse is studied in detail.

The adsorption (kinetics and signal stability) of cationic triarylmethane dyes and an acridine derivative with various counter-ions on citrate-stabilized hydroxylamine-reduced silver sols was studied using SERS spectroscopy. The influence of the method of nanoparticle synthesis, as well as the composition and ionic strength of the medium on the stability of nanoparticle–dye complexes was investigated.

The luminescence kinetics of the electron transition ⁵D₀ → ⁷F₂ (~613 nm) of Eu³⁺ ions has been studied in tungstates (Lu_{1 – x}Eu_x)₂(WO₄)₃ and molybdates (Lu_{1 – x}Eu_x)₂(MoO₄)₃. Luminescence decay times are very close in both compounds at x ≥ 0.2, while a significant difference is observed at x < 0.1. Observed behavior is attributed to the difference in electronic structure of compounds.

The main design options for supplying SHF energy to the end wall of a cylindrical resonator were considered. 2 types of designs for coaxial feed of energy were selected and optimized, differing in the location of the coaxial line relative to the required direction of wave propagation. As a result of the calculations, the electric fields inside the cylindrical chamber and in the horn coaxial antennas were found, and the SWR of the systems was determined. A comparison in distribution of the electric field when metal objects were placed in the chamber was carried out. The areas of occurrence of a plasma SHF discharge on the surface of a cylindrical object were shown.

We presented the results of a comparison of the analytical study of the features of the radial distribution of MHD disturbances of the magnetic field components in the body of a model solar wind magnetic cloud with data on a real cloud recorded by a spacecraft. The analytical-numerical solution for perturbations is performed in a cylindrical coordinate system for a cloud represented by a force-free cylindrical tube with a helical magnetic field. The obtained general idea of the radial distribution of the magnetic field components in the MC body is consistent with the registered parameters of the magnetic field disturbances on the patrol spacecraft and is confirmed by an objective correlation analysis. Joint post-processing of the counting results and real data compared with them enhances the consistency, which indicates the adequacy of the applied MHD approach to the analysis of oscillations in the model body of the magnetic cloud.

We considered numerical modeling of the current sheet in the Jupiter’s near magnetotail to estimate the possible range of parameters of this layer depending on the presence of hot sulfur and oxygen ions. The characteristics of the obtained stationary configurations of the current sheet formed by counterflows of either protons alone, or oxygen ions alone, or sulfur ions alone, are in good agreement with the Juno’s data.

Event GLE66 (29.10.2003) is a selected study in a series of three GLE events that occurred in the fall of 2003. there was this most powerful magnetic storm and a deep Forbush effect, during which GLE66 occurred. The appearance of the T-05 drilling model of the magnetosphere and the availability of a methodology debugged on dozens of less complex GLE events for solving the problem of achieving results for this complex event. Obtaining the values of the parameters of the cosmic ray flux at subsequent moments of time. A pattern typical of GLE events is observed: the spectrum of observed cosmic rays at the initial phase has an exponential shape, and then ends in a power law. The obtained spectra are in good agreement with measurements of cosmic ray precipitation on spacecraft at lower energies.

Experimental data on the registration of signals from tweek-atmospherics and an ionospheric source formed because of heating of the ionosphere at frequencies higher than the frequency of the first transverse resonance of the Earth–ionosphere waveguide (~1.8 kHz) are considered. It is shown that, far from the source, at frequencies near the resonance, almost complete circular left-hand polarization of the horizontal magnetic field is observed, and the angles of incidence are small and range from 10° to 35°. A joint analysis of observational data and simulation results showed that it is possible to calculate the effective reflection height from estimates of the incidence angle, which can be used to diagnose the lower ionosphere. But, in the case of an ionospheric source, it is important to take into account the inhomogeneity of its radiation pattern.

It is shown that the efficiencies of excitation of optical emissions λ = 391.4, 557.7, and 630.0 nm and the efficiency of formation of the total electron density weakly depend on the shape of the energy spectrum of precipitating electrons and are mainly determined by the values of the average energy of the electron flux.