Abstract This paper presents the results on the synthesis and study of the properties of monolayer and multilayer films obtained by pulsed laser deposition on glass substrates. Atomic force microscopy (AFM), X-ray diffractometry, Raman scattering spectroscopy, optical absorption, photoluminescence and Hall measurements were used to characterize the structural, morphological, optical and electrical

Abstract The generation of the THz radiation in a nonlinear single-domain lithium niobate crystal is considered. The lasing efficiency is investigated as a function of the angle between the directions of propagation of the exciting laser beams at different beam radii and the THz radiation wavelength. The angular distribution of the generated radiation is investigated. It is shown that it is possible

Abstract The performance of a pentacene organic thin film transistor (OTFT) is discussed here where the substrate consists of a self-assembled monolayer (SAM) formed from octadecyltrichlorosilane (OTS) on the gate insulator. By changing the substrate from hydrophilic to hydrophobic interface defects are minimized. OTS SAM was studied for two samples according to OTS density 0.5 wt % and 1.0 wt % based

Abstract Two-dimensional tin dioxide is a promising material that can be widely used in gas sensors. The interaction of water molecules with two-dimensional tin dioxide was investigated in this work using first principles (ab initio) methods. The adsorption energies, charge transfer, density of states and electron localization functions (ELF) are calculated for various adsorption structures. As a result

Abstract In this work, a simple and effective method for the synthesis of carbon nanotubes, and graphene-based quantum dots is described. The topological properties of these nanostructures are studied by atomic force and scanning electron microscopes. The potential of quantum dots is investigated by the Kelvin probe method. To study the formed bonds and for a detailed structural analysis, Raman spectroscopy

Abstract We present the results of an experimental study of the occurrence of electric current in water during interaction with acoustic waves. Besides the presence of the weak acoustoelectric effect, a new resonant acoustogalvanic phenomenon in water was also discovered. Possible reasons for the small value of the acoustoelectric current and the physical mechanism of the appearance of the acoustogalvanic

Abstract The practical aspect of nanotechnology includes the production of devices and their components needed to create, process and manipulate atoms, molecules and nanoparticles. The phenomena of aging and self-heating significantly affect the operation of microelectronic circuits. This paper developed a model of a three-bit, parallel analog-to-digital converter with low power consumption, as a result

Abstract Hydrogen-like impurity states in a semiconductor nanoplatelets in the shape of a rectangular parallelepiped of small thickness are investigated within the framework of the variational method. It is shown that, due to the small thickness of the nanostructure, the impurity can be considered two-dimensional one. In the case of a divalent impurity, the electron-electron interaction is also considered

Abstract Laser-induced hydrodynamic (LIH) motions in nematic liquid crystal (NLC) which is an initially oriented hybrid have been studied theoretically. For the direction when the flow velocity is directed out of the “flexible ribbon’s” curvature, it brings an increase of the curvature. But when the velocity has the opposite direction, we have two different cases depending on the surface anchoring

Abstract It is demonstrated that reflection of a continuous-wave single-frequency laser radiation from a thick flat-parallel glass wafer can be used for precise remote measurement of temperature. Such measurement relies on the low-finesse Fabry-Pérot nature of the dielectric wafer, whose optical thickness depends on temperature due to two characteristics of the dielectric material: the linear expansion

Abstract The scientific and technical status after renovation and restoration works of the linear electron accelerator LUE-75 of the Alikhanyan National Science Laboratory is presented, and some computed data on the effect of frequency, phase, and temperature changes in the high-frequency power supply path and the accelerating system on the stability of the electron beam energy, associated with the

Abstract The undulator radiation of positrons channeled in a crystalline undulator with sections (CUS) is investigated theoretically taking into account the effect of dielectric polarization of the crystalline medium. The configuration of CUS preserves planar channeling of positrons with a given energy. An analytical expression is obtained for the spectral distribution of the number of radiated photons

Abstract In this paper the combined effect of intense terahertz laser radiation and external homogeneous magnetic field on electron states and magnetization of GaAs quantum ring is investigated theoretically. The effect of laser field is calculated using the dipole approximation and Kramers–Henneberger unitary transformation. The temperature effect on magnetization of the system is also considered

Abstract The electrical characteristics and photoresponse of the “carbon nanofilm on silicon” heterostructure obtained by laser-pulsed deposition have been investigated. The thickness of the carbon nanofilm is selected from the condition of the maximum antireflection effect of the substrate. It was found that the obtained junction is rectifying with a rectifying coefficient of 35 at 1 V. The direct

Abstract Break-up of a cw 632.8 nm wavelength laser beam to regular optical patterns during propagation through a photorefractive iron doped lithium niobate (LN:Fe) crystal is demonstrated. The power of the laser beam is varied in the range of 0.02–10 mW and 4 and 10 mm lengths LN:Fe crystals are used in the experiments. Time evolution of the laser beam profile at the output face of the LN:Fe crystal

Abstract The problem of the character of the oscillation phase at different points of the wave field of a system of two point and isotopically emitting sources is discussed. This issue is considered for the points located on the surfaces of the maxima and minima of the interference picture. It is also shown that on the surfaces of the amplitude extrema, the in-phase or antiphase oscillations are determined

Abstract Our article is devoted to the computation of two three-loop diagrams that contribute to the decay \(b \to s\gamma \) at \(\alpha _{s}^{2}\) order. We use differential equations for master integrals (MI) to compute these diagrams for an arbitrary c-quark mass. The program CANONICA is used to obtain differential equations on a canonical basis. Using them, it is possible to solve the differential

Abstract This article considers biexciton states in a cylindrical quantum dot in the strong dimensional quantization regime and shows the stability of the biexciton. A cylindrical quantum dot is limited in the axial direction by the parabolic potential, but in the radial direction – by the Morse potential. The dependences of the energy of the ground state of the biexciton on the geometric parameters

Abstract The electron-hole states in a cylindrical quantum dot with a limiting parabolic potential, as well as a modified Pöschl-Teller potential in the regime of strong dimensional quantization, are investigated. Expressions are found for both the energy and the wave functions of particles in the radial and axial directions. Expressions for the radial energy are obtained for various modes of magnetic

Abstract The results of experimental studies of the anti-reflection properties of black silicon (b-Si) layers coated with thin films of TiO2, HfO2, and Sc2O3 metal oxides by atomic layer deposition (ALD) are presented. An improvement in the antireflection properties of b-Si in a wide spectral range is shown. It is expedient to use the investigated ALD films in solar cells as an effective passivating

Abstract Nanoparticles of iron (α-Fe) and iron oxide (Fe3O4) with a core-shell structure (α-Fe core, Fe3O4 shell) covered with additional graphite-like carbon layer have been synthesized. The samples were obtained by solid-phase pyrolysis of iron phthalocyanine (FePc) at a pyrolysis temperature of 1000°C, followed by annealing in an oxygen atmosphere at a temperature of 250°C. The composition, structure

Abstract An experimental set-up for hard X-ray off-axis Fresnel holography, based on a two-block Fresnel zone plates interferometer is proposed and analyzed. It is shown, that the suggested scheme provides a recording of the hologram and further numerical reconstruction of the image. The advantage of this scheme, compared with the earlier presented analogous scheme of on-axis holography, based on the

Abstract Doping of thermoelectric materials with various additives is a promising approach for increasing the functional efficiency of thermoelectric materials of different classes. This paper presents preliminary results of studying the impact of the strontium borate dopant Sr(BO2)2 on the power factor (PF) of the oxide thermoelectric Bi2Sr2Co1.8Oy. Samples with the nominal composition Bi2Sr2–x[Sr(BO2)2]xCo1

Abstract The aim of this study is the further development of the technology of Ga67 medical radioisotope production by irradiating a zinc target with natZn67(p,xn)Ga67 reaction. The irradiation was carried out with a proton beam generated by C18 cyclotron which was put into operation in June 2019 in the vicinity of the A. Alikhanyan National Science Laboratory (YerPhI). At present, the cycle of research

Abstract The verification scheme in the package “Professor2” for setting parameters of the most used physics generator PYTHIA8.2 for simulating the processes in high energy physics is described. The goal is to tune the PYTHIA8.2 parameter list for the fragmentation process below \(b\bar {b}\) the production threshold. As an initial parameter list, we use the Belle (predecessor of the Belle II experiment)

Abstract The state of polarization is an important feature of any laser emission. The polarization of light is important for the processing of laser beams in polarization-dependent devices such as interferometers, optical amplifiers, optical modulators, etc. In this paper, the polarization of lasing generated from the three-layered cholesteric liquid crystal–dye-doped polymer layer–cholesteric liquid

Abstract The use of a method developed in the CLAS collaboration (Jefferson Lab, USA) to extract events of quasi-real photoproduction on nuclei from experimental data of electroproduction, as applied to the reaction of near-threshold photoproduction of the J/ψ-meson is described in this paper. Experimental data of electroproduction on a liquid hydrogen target, which was obtained on CLAS12 experimental

Abstract A technology has been developed for obtaining a semiconductor solid solution SnO2 + Nb2O5 (80 : 20 wt %) and for manufacturing a thin-film nanoscale resistive sensor. The gas-sensitive characteristics of the sensor to various concentrations of liquefied petroleum gas (LPG) have been investigated. The SnO2❬Nb❭ sensor detects sensitivity to LPG from an operating temperature of 250°C when exposed

Abstract Coupled cycloidal diffractive waveplates (CDWP) can be used for double diffraction or collinearly propagation of laser radiation of the corresponding wavelength. Adding a doubly refracting and dichroic film between them enables one to obtain the finite transmission even in the absence of double refraction. Both in the cases of two parallel and antiparallel vector gratings, we have an achromatic

Abstract The paper presents and discusses works carried out both at Yerevan State University and abroad on non-invasive metal oxide sensors (chemiresistors) for acetone exhaled by a diabetic. The technologies and parameters of chemiresistors based on tin dioxide, tungsten trioxide, zinc oxide, Fe2O3, In2O3 and TiO2 developed at YSU and in the world are presented. Most likely, it makes sense to start

Abstract A sensor sensitive to acetone vapors based on a Fe2O3❬Sn❭ metal oxide solid solution was fabricated by high-frequency magnetron sputtering. The gas-sensitivity of the manufactured sensor are investigated. The Fe2O3❬Sn❭ sensor shows sensitivity to acetone vapors starting from a temperature of 150°C under the influence of ultraviolet rays. The increase in operating temperature was accompanied

Abstract To get around the difficulty that the singular nature of the potential function V(x) = V0/|x|α introduces into physics, the regularization methods are used. However, they affect the singular nature of the problem, and so we discuss here how quantum tunneling behaves if the original singular nature of the Schrodinger equation remains unperturbed. For this purpose, I am starting from the precondition

Abstract Results of the characterization and numerical analysis of InAsSbP composition strain-induced micro- and nanostructures shape transition are presented. Nucleation is performed from In-As-Sb-P quaternary composition liquid phase in Stranski–Krastanow growth mode. Geometric features and the shape transformation chronology of truncated pyramidal islands, lens-shape and pyramidal quantum dots (QDs)

Abstract New expressions have been obtained to estimate the graphene thermal conductivity coefficient as well as characteristic dependences of coefficient of thermal conductivity on temperature and linear coefficient of thermal expansion. It has been shown that within a wide range of temperatures (about 100–700 K), the thermal conductivity values both computed and experimental ones are in good agreement

Abstract Under the two-wave dynamical diffraction conditions, the wave-field passed through a periodic object is formed in a crystal. The dynamical diffraction Talbot effect in the crystal takes place. The estimates for the required spatial and temporal coherence of the incident radiation are provided.

Abstract For better visualization of solvent effects on spin-spin coupling constants (SSCCs) we have investigated some organomercury compounds, which have large solvent induced changes on one-bond C-Hg SSCCs. Extra large solvent effects (up to 20% of SSCC value) have been observed, which allow to more carefully examine the peculiarities of SSCC’s solvent and electric field dependencies in various media

Abstract This paper reports the results of the investigation of second order optical nonlinearity, as well as the polarization nonlinear behavior of Zn4B6O13. For experiments samples were prepared by thermal treatment of glass tapes and solid state synthesis. The tapes were obtained by a rapid melt quenching technique. The thermal processes in the glass tapes were investigated by differential thermal

Abstract The binding peculiarities of methylene blue (MB), methyl violet (MV), and Hoechst 33258 (H33258) with human serum albumin (HSA) have been studied using the fluorescence spectroscopy method. Based on the fluorescence spectra analysis, it was shown that the HSA binds to the all mentioned ligands and forms complexes, meanwhile, a quenching of the ligand fluorescence occurs, which was found to

Abstract The results of the simulation modeling of single-stranded DNA adsorption on the surface of a single-walled carbon nanotube performed by the molecular dynamics method using the GROMACS software package are presented. The dependence of the timescale and degree of the DNA adsorption was studied against the chirality of the carbon nanotube and the DNA sequence.

Abstract The production of the therapeutic 186gRe radioisotope by proton-induced natW(p,xn) reaction at the cyclotron C18/18 was investigated. The cyclotron is located at the A. Alikhanyan National Science Laboratory (Yerevan Physics Institute). The excitation function of the reaction in the proton energy range from the reaction threshold up to 18 MeV was measured. The measurements were carried out

Abstract Noninvasive in vivo measurements of glycemia in 8 living non anesthetized mice were done using a microwave spiral sensor (MSS). The D-glucose concentration in the blood of the animals was measured in the 80–350 mg/dL concentration range using microwaves of frequencies from 4–5 GHz. Aqueous D-glucose solution with concentrations from 0 to 6% was orally injected into the mice and the change

Abstract The behavior of iron in the translucent dark-gray obsidian from the Artheni deposit was studied by optical absorption and EPR spectroscopy. The presence of iron in the Fe2+ and Fe3+ states was shown. Transitions in optical spectra and paramagnetic centers in EPR spectra were identified. By the methods of prompt gamma activation analysis (PGAA) and neutron activation analysis (NAA), the content

Abstract The results of modeling heat propagation processes in the four-layer SiO2/W/FeSb2/W detection pixel of thermoelectric single-photon detector after absorbing more than one IR photon are presented. The calculations were carried out by a three-dimensional matrix method for partial differential equations. The cases of both simultaneous absorption of several photons on a 1-μm segment of the absorber

Abstract In this work, a theoretical model of the full population transfer in a five-level M type system is demonstrated. The method is based on the technique of linear scanning of the frequency of the laser field close to the resonance frequency of the corresponding transition. A comparison of the full population transfer obtained with the chirping technique with the results obtained by the method

Abstract Wind energy is one of the main factors in the future transition to renewable energies. Hence, it is important to understand how much work can be extracted from the kinetic energy of the wind. Understanding these constraints is important for setting correct strategic goals in wind power research and industry. The current standard opinion is that the limits on the efficiency of work-extraction

Abstract A microwave (MW) method has been developed for the preparation of a ZnO/Ag nanocomposite using methods of chemical precipitation and decomposition of thermally unstable compounds. Chemical co-deposition is a simple and efficient method in comparison with other methods of obtaining a ZnO/Ag nanocomposite. The characteristics of the synthesized product were determined by differential thermal

Abstract In the present work, statistical processing of the electric cardiogram (spectral and bispectral analysis) using the ‘sliding window’ method is proposed and performed. A system for recording and digitizing an electric cardiograms was developed, the output signal of which is fed to a computer. Signal processing is carried out using a system implemented in the LabVIEW environment. It is shown

Abstract The diffraction of an electromagnetic wave from a round hole on an opaque screen is studied when there is no vacuum on the opposite sides of the screen, as is usually considered, but on one side there is a refractive medium and on the other—vacuum. The diffraction peculiarities due to the fact that the medium into which the wave penetrates from the vacuum have a refractive index different

Abstract The pseudobinary HgTe–CdTe, ZnTe–CdTe and HgTe–ZnTe systems were studied and Gibbs energy of mixing were determined at 400–1000 K temperature range. Miscibility gap analysis for CdZnHgTe quaternary material system is also performed by the Gibbs free energy calculations. Quantitative explorations show that there is no immiscibility gap for CdTe–HgTe material system in the mentioned above temperature

Abstract A better theoretical understanding of the atom – surface interactions and of the experimental consequences and applications to a reproducible method for the construction of reliable coated absorption cells is the main scope of our research. In this paper we report on the influence of diode laser intensity and of diode frequency scanning rate on the spectrum of the D2 line of Rb atoms, contained

Abstract The review discusses the results of studies of gas sensors based on zinc oxide. Possibilities and technologies for the manufacture of such sensors are mentioned. ZnO sensors undoped, doped with impurities and carbon nanotubes, as well as sensors based on nanowires and quantum dots are considered. Possibilities of decreasing the operating (working) temperature of heating the working body of

Abstract We describe the application of the phase plane method to analyze the behavior of stationary harmonic plane electromagnetic waves. The phase plane method allows one to describe qualitatively all possible solutions of the Helmholtz nonlinear differential equation without performing a numerical integration. All types of phase portraits for waves in the media with self-action are presented and

Abstract A finite boson representation of fermion operators is obtained. The collective Hamiltonian for a description of the pair excitation is constructed and the collective potential energy is analyzed. The collective modes related to the addition and removal of pair of particles are partitioned off the variety of nuclear degrees of freedom.

Abstract At the RKFM stations in the NRC ‘Kurchatov institute’ the peculiarities of the effect of redistribution of the intensity of the diffracted synchrotron beam in the X-cut quartz crystals at the excitation of transverse resonant ultrasonic vibrations were studied. The dependences of the intensity of the diffracted X-ray beam on the resonant frequency voltage of the signal are obtained, and it

Abstract This work considers the spin-1/2 Heisenberg dimer, the mixed spin-(1/2,1) Heisenberg dimer and their quantum entanglement, particularly, the dependence of the entanglement on the system characteristics and the external magnetic field. The quantum entanglement in this work is determined using two different methods, namely ‘Negativity’ and ‘Concurrence’. The dependence of the corresponding quantities

Abstract Solar photovoltaic-thermal (PVT) hybrid systems have the high potential to be an effective and viable method for producing electricity and thermal energy for low grade heating application. The hybrid system is highly energy efficient with improved electrical efficiency due to cooling of solar cells and gained thermal energy due to heat absorbed by the fluid from the heated cells. Nevertheless

Abstract The features of the energy spectrum and the movement of carriers in one-dimensional asymmetric semiconductor nanosystems are considered. Asymmetric structures with an additional dip in the potential profile in the quantum wells allow one to vary the positions of the dimensionally quantized levels. An additional influence of the external magnetic field leads to non-monotonic dispersion and

Abstract Antireflection layers are an important part of the sensitive elements of high performance single photon detectors. We have obtained amorphous silicon dioxide films by electron-beam sputtering on Al2O3, AlN, Si substrates as well as CeB6, LaB6, and W coatings. The elemental composition, microstructure and surface roughness, as well as optical characteristics of the samples obtained under various

Abstract The spontaneous emission of a spherical semiconductor quantum dot is considered without using the dipole approximation. It is shown that the dipole-forbidden radiation of a shallow potential well with one electron level becomes more intense than the dipole-permitted radiation of a deeper potential well and that the potential deepening makes the dipole approximation closer. It is also shown

Abstract A theoretical study of the spectroscopic properties of the low-phonon LaF3:Er3+ crystals determining their laser capabilities in the mid-infrared wavelength range (2.62–4.97 μm) was carried out. The wave functions of the Stark sublevels of 4S3/2, 4F9/2, 4I9/2, 4I11/2, and 4I13/2 of Er3+ ion are constructed by the LSJM-representation. The line strengths of the indirect electric dipole and magnetic