bluuebunny/crossref_metadata_2025_split huggingface dataset:
Photoemission from p-GaAs(Cs,O) under transition from negative to positive electron affinity
Authors: Protopopov D E , Khoroshilov V S , Zhuravlev A G , Kazantsev D M , Alperovich V L 
Published: December 2020

Abstract
The evolution of the electron escape probability from p-GaAs(Cs, O) to vacuum was measured under the transition from the state of negative to the state of positive electron affinity. The transition was induced by the deposition of excess cesium or oxygen on the p-GaAs(Cs, O) surface activated to the state of negative electron affinity. Under deposition of excess cesium, the escape probability was significantly lower as compared to excess oxygen, presumably, due to reflection and scattering of electrons on two-dimensional cesium metal clusters. Under Cs-induced transition, at positive values of affinity, a new peak was observed below the band gap in the photoemission quantum yield spectra. The peak stems, presumably, from: (i) the effective capture of sub-bandgap light in the structure, which consists of the heavily doped p
+-GaAs epilayer grown on the semi-insulating GaAs substrate, due to diffuse backside reflection from the rough back surface of the substrate; (ii) absorption of the captured light near the emitting p
+-GaAs surface due to the Franz-Keldysh effect in the strong surface electric field; (iii) emission of the electrons generated near the surface.
Optical method for determination of fatigue damage in organic glass
Authors: Sinicyna E A , Nagornaya A I , Kulikova M E , Davydov V. V. , Glinushkin A P 
Published: December 2020

Abstract
The features of nucleation, start, and propagation of a crack inside a transparent organic sample are investigated. The distribution of the refractive index and density around the crack was studied by changing of speckle images and ellipsometry method. It was found that the maximum value of the relative change in density is near the crack. This value before the crack start is greater than 0.003. It is proved that the speckle method we offer can be the basis for the creation of various techniques. Using these techniques will allow us to estimate the time before the crack start by the rate of change of physical quantities in small areas of the order of 50 μm and their limiting values. The results of experimental investigations are presented.
Simulation of the super-Gauss beam abrupt focusing in the near diffraction zone using high-performance computer systems
Authors: Savelyev D A , Volotovskiy S G 
Published: December 2020

AbstractWe investigated the change in the type of focal spot when laser radiation passed through the diffraction axicon and the optical element matched with the circular Airy distribution having abrupt focusing properties. Modelling of near zone diffraction is numerically investigated by the finite difference time domain (FDTD) method. The abrupt formation of a light needle was shown for the optical element matched with the circular Airy distribution and for axicon.
Wave-vector direction-sensitive photocurrent in laser-induced graphene
Authors: Mikheev K G , Fateev A E , Zonov R G , Bulatov D L , Mikheev G M 
Published: December 2020

Abstract
Porous graphene film structures were formed in the process of line-by-line scanning by a focused laser beam of cw CO2 laser on polyimide film. It was shown that at a power density of 8 W/cm2 and a scanning speed range of 200-260 mm/s, porous graphene is formed on the surface of a 120-μm-thick polyimide film. The results of the investigation of the longitudinal photocurrent generation in LIG film are presented. Photocurrent excitation was carried out by nanosecond laser pulses at wavelength range of 266-1064 nm. It was found that the photocurrent depends on the direction of the wave-vector of the incident radiation according to the odd law characteristic of the photon drag effect (PDE). It is also shown that the presented method of the LIG film formation leads to anisotropy of its photovoltaic properties.
Study of microheater’s phase modulation for on-chip Kennedy receiver
Authors: Venediktov I O , Elezov M S , Prokhodtsov A I , Kovalyuk V V , An P P , Golikov A D , Shcherbatenko M L , Sych D V , Goltsman G N 
Published: December 2020

Abstract
In this work we describe phase modulators for several Mach-Zehnder interferometers (MZI) on silicon nitride platform for telecomm wavelength (1550 nm). We obtained current-voltage and phase-voltage curves for these modulators. MZI are needed for experimental realisation of various quantum receivers that can distinguish weak coherent states of light with extremely low error. Thermo-optical (TO) modulation is ensured by microheaters on one of the arms of MZI, which enables the change of the refractive index of the material with temperature. This approach allows to apply the necessary voltage to the golden microheaters to obtain the required phase change. For the on-chip microheaters we demonstrate the dependence of the phase shift on the voltage applied to our on-chip microheaters.
Intercept-resend attack on passive side channel of the light source in BB84 decoy-state protocol
Authors: Babukhin D , Sych D 
Published: December 2020

Abstract
Quantum key distribution (QKD) promises unconditionally secure communication based on fundamental laws of physics, though practical realizations of QKD may have loopholes and side channels, thus their security can be compromised. We analyze the intercept-resend attack on the BB84 decoy-state protocol under the presence of a passive side channel of the light source. We derive an upper bound for the secret key rate and show that it does not significantly deviate from the ideal side-channel-free case.
Formation of silver nanoparticles in ion-exchanged glass with nanosecond laser irradiation
Authors: Morozova O , Babich E , Kaasik V , Raskhodchikov A , Raskhodchikov D , Zhurikhina V , Lipovskii A 
Published: December 2020

Abstract
We studied the irradiation of silver enriched soda-lime glass slides by 6 nanosecond long laser pulses at the wavelengths of 1064 and 532 nm. The extinction spectra of the irradiated glass regions after the laser exposition and after chemical and reactive ion etching (RIE) were compared. Independently on the wavelength, the irradiation resulted in the formation of silver nanoparticles demonstrating localized surface plasmon resonance (LSPR), which gradually disappeared with the etching of the samples. The dependence of the spectral position of LSPR on the etching time was significantly different for chemical etching and RIE. We relate this to the chemical interaction of silver with the gases used in RIE.
Dielectric surrounding bleaches the optical bond between a microdisk resonator and a straight optical waveguide
Authors: Raskhodchikov A V , Scherbak S A , Kryzhanovskaya N V , Lipovskii A A , Zhukov A E 
Published: December 2020

Abstract
We performed a numerical study of a surrounding medium influence on coupling efficiency between a microdisk resonator supporting optical whispering gallery modes and a straight optical waveguide. Quality factors of the modes and relative optical power coupled to the waveguide were calculated using COMSOL Multiphysics environment. It was shown that the most efficient coupling takes place when propagation constants of the modes of the microdisk and the waveguide match. The coupling can be significantly strengthened by increasing the index of the surrounding medium.
To the issue of the second harmonic generation in poled silicate glasses
Authors: Reshetov I V , Kaasik V P , Lipovskii A A , Tagantsev D K 
Published: December 2020

Abstract
Thermal relaxation of the second harmonic generation (SHG) observed in thermally poled soda-lime silicate glass is studied. At least two relaxation processes could be distinguished. Determined activation energy of the fastest SHG relaxation process is equal to about 0.5 eV. This SHG relaxation occurs at temperatures essentially below ones, at which the thermally stimulated depolarization current (TSDC) measurements show the relaxation of the spatial charge formed in thermal poling of the glasses. This confirms that SHG in poled glasses is not mostly conditioned by the “frozen” spatial charge and electric field of this charge.
Enhance of the superconducting properties of the NbN/Au bilayer bridges
Authors: Simonov N O , Korneeva Yu P , Korneev A A , Goltsman G N 
Published: December 2020

Abstract
We experimentally demonstrate strong temperature dependence of the critical current of the superconducting 600-nm-wide and 5-μm-long bridge made of NbN/Au bilayer. The result is achieved due to the proximity effect realized between the highly disordered superconducting NbN layer and low resistive normal-metal Au layer.
Calculation of a binary diffractive optical element to increase the imaging system depth of field in the task of classifying images by a neural network
Authors: Dzyuba A P , Khonina S N , Nikonorov A V , Serafimovich P G 
Published: December 2020

Abstract
Using an example of a real-world data set, it is shown that the accuracy of the image classifier based on a convolutional neural network does not deteriorate when using only one color channel. The binary diffractive optical element was calculated, which allows to increase the imaging system depth of field by several times. This is achieved by using the different color channels for various defocus values. A comparison of the MTF curves of the original and apodized imaging systems for a given minimum acceptable value of image contrast is presented.
Sensitivity Features of Double-Resonance Plasmonic Sensor
Authors: Tomilin S V , Karavaynikov A V , Tomilina O A , Berzhansky V N 
Published: December 2020

Abstract
The paper presents the results of a model investigation about the temporal dynamics of changes in the resonance excitation conditions of surface plasmon-polariton waves in a double-resonance plasmonic sensor at different thicknesses of the sensitive ligand layer. It was shown that the maximum sensor reaction rate to the emergence of analyte is observed at a ligand layer with 40–50 nm thickness. When the ligand layer thickness is less than 40 nm, the sensitivity of the sensor decreases sharply, and when the ligand thickness is increase over 60 nm, a delay in the sensor reaction is observed which due to the limited diffusion rate of the analyte into the ligand. The most effective mode of a plasmon sensor operation is the mode in which the angle of the exciting beam incidence is somewhat different from the resonance angle at condition when the analyte is absent.
The Influence of Dielectric Environment on Spectral Shift of Localized Plasmonic Resonance
Authors: Tomilina O A , Berzhansky V N , Tomilin S V 
Published: December 2020

Abstract
In paper the investigation results of dielectric environment influences on spectral shift of localized plasmonic resonance in a system of self-assembled metallic nanoparticles was introduced. It was shown, that the value of spectral shift of localized plasmonic resonance has a linear proportion towards the changes of environment refractive index. For investigated plasmonic system of self-assembled Au nanoparticles the coefficient of proportionality was determined.
Peculiarities of the synthesis of GST films by magnetron sputtering for nonvolatile optical memory cells
Authors: Korolev D S , Sidorenko K V , Nikolskaya A A , Mikhaylov A N , Chigirinsky Y I , Minnullin R T , Makarov M E , Sapegin A A , Barabanenkov M Yu 
Published: December 2020

Abstract
The structure and optical properties of thin films of the chalcogenide semiconductor Ge2Sb2Te5, deposited by magnetron sputtering, was studied. A significant change in the topology and optical properties of the films is demonstrated with varying deposition conditions. It is shown that an increase in the deposition time leads to an increase in the surface roughness. Doping with nitrogen during deposition leads to a smoothing of the film surface, and also provides a strong change in the band structure and optical properties.
Peculiarities of the electronic and magnetic characteristics in Co2
YSi (Y = Ti, V, Cr, Mn, Fe, Co, Ni) Heusler alloys close to the half-metallic ferromagnets and spin gapless semiconductors
Authors: Perevozchikova Yu A , Semiannikova A A , Korenistov P S , Marchenkov V V 
Published: December 2020

Abstract
The Hall Effect and magnetization of Heusler alloys Co2YSi (Y = Ti, V, Cr, Mn, Fe, Co, Ni) were measured at T = 4.2 K and 300 K in magnetic fields of up to 100 kOe as well as the temperature dependence of the electroresistivity from 4.2 to 300 K. The normal and anomalous Hall coefficients, saturation magnetization, residual resistivity, type and concentration of current carriers and their mobility were obtained. It was demonstrated that there is a clear correlation between the electronic and magnetic parameters obtained, depending on the number of valence electrons z, at the transition from Co2TiSi (z=26) to Co2NiSi (z=32). The observed peculiarities of electronic and magnetic parameters may be due to the appearance of the states of the half-metallic ferromagnet and/or spin gapless semiconductor.
Anomalous Nernst-Ettingshausen effect in diluted magnetic semiconductors
Authors: Kuznetsov Y , Dorokhin M , Kudrin A. , Ved M , Lesnikov V 
Published: December 2020

Abstract
The magnetic field dependences of the Hall and Nernst-Ettingshausen effects in (In, Fe)Sb, (Ga, Fe)Sb, (Ga, Mn)As diluted magnetic semiconductors were investigated. The samples were fabricated on a semi-insulating GaAs substrates by pulsed laser deposition in vacuum. The manifestation of the anomalous Nernst-Ettingshausen effect along with the anomalous Hall effect in manganese-containing structures was shown experimentally. It is demonstrated that the difference in the magnetic field dependences of the Hall and Nernst-Ettingshausen effects in systems with Mn and Fe is due to the different nature of ferromagnetism.
An artificial neural network as a predictor of electrical characteristics of nanoelectronic device channel based on a low-dimensional heterostructure
Authors: Vetrova N A , Pchelintsev K P , Shashurin V D 
Published: December 2020

Abstract
In this paper a computational algorithm for calculating current density of low-dimensional semiconductor heterostructures based on an artificial neural network is proposed. The neural network training is performed using the quantum-mechanical model of Green’s Functions.
Test element for high voltage SiC Schottky diodes quality control
Authors: Sedykh S V , Rybalka S B , Kulchenkov E A , Demidov A A , Drakin A Yu , Bryukhno N A , Kuftov I V 
Published: December 2020

Abstract
The test element for quality control of SiC Schottky type high voltage diodes has been constructed at first in this study. It is shown that proposed test element give possibility for determination of important parameters for testing diode before Schottky contact formation and therefore can be decrease production costs in production of SiC Schottky type high voltage diodes.
Planar Schottky diode with a Γ-shaped anode suspended bridge
Authors: Shurakov A , Mikhailov D , Belikov I , Kaurova N , Zilberley T , Prikhodko A , Voronov B , Vasil’evskii I , Goltsman G 
Published: December 2020

Abstract
In this paper we report on the fabrication of a planar Schottky diode utilizing a Г-shaped anode suspended bridge. The bridge maintains transition between the top and bottom level planes of a 1.4 µm thick GaAs mesa. To implement the profile of a suspended bridge and inward tilt of a mesa wall adjacent to it, we make use of an anisotropic etching of gallium arsenide. The geometry proposed enables the fabrication of a diode with mesa of an arbitrary thickness to mitigate AC losses in the diode layered structure at terahertz frequencies of interest. For frequencies beyond 1 THz, it is also beneficial to use the geometry for the implementation of n-GaAs/n-InGaAs heterojunction Schottky diodes grown on InP substrate.
Efficiency of a microwave reflectometry for readout of a THz multipixel Schottky diode direct detector
Authors: Shurakov A , Prikhodko A , Mikhailov D , Belikov I , Kaurova N , Voronov B , Goltsman G 
Published: December 2020

Abstract
In this paper we report on the results of investigation of efficiency of a microwave reflectometry for readout of a terahertz multipixel Schottky diode direct detector. Decent capabilities of the microwave reflectometry readout were earlier justified by us for a hot electron bolometric direct detector. In case of a planar Schottky diode, we observed increase of an optical noise equivalent power by a factor of 2 compared to that measured within a conventional readout scheme. For implementation of a multipixel camera, a microwave reflectometer is to be used to readout each row of the camera, and the row switching is to be maintained by a CMOS analog multiplexer. The diodes within a row have to be equipped with filters to distribute the probing microwave signal properly. The simultaneous use of analog multiplexing and microwave reflectometry enables to reduce the camera response time by a factor of its number of columns.
Features of signal transmission through a fiber-optic system for an interference compensation module for an active phased array antenna
Authors: Moroz A V , Davydov V V , Malanin K Yu 
Published: December 2020

Abstract
The article describes the operation of the X-band radar under the influence of active and passive interference. The rationale for using the interference compensation module in a radar station with a small-sized active phased array antenna is presented. A fiber-optic system has been developed for transmitting a signal from a compensation module. The results of experimental studies of the transmission system are presented. The advantages of using a fiber-optic system in a radar station in comparison with a coaxial cable are shown.
The spin-filtering properties in two coupled Rashba quantum rings
Authors: Smolkina M O , Popov I Ju , Blinova I V 
Published: December 2020

Abstract
The spin-dependent electron transport in two coupled quantum rings with Rashba spin-orbit interaction and magnetic flux was studied by using quantum waveguide theory. We show the dependence of spin-polarization on system parameters such as the Rashba coupling constant, the radius of the rings, the angles between the leads and the attachment point of the rings. The spin-polarization can be controlled and changed from -1 to +1 by using a magnetic flux. Also it was shown that this model is a limiting case of double Rashba quantum ring when the length of the middle lead between rings vanishes. The same study for spin-filtering properties in two coupled quantum rings with Dresselhaus spin-orbit interaction was also obtained and the results were compared.
Modeling of the protective coatings formation mechanism by micro-arc oxidation
Authors: Golubkov P E , Pecherskaya E A , Melnikov O A , Zinchenko T O , Kozlov G V , Antipenko V V 
Published: December 2020

Abstract
An electrophysical model of the micro-arc oxidation process, which allows, on the basis of the equivalent electrical circuit and fundamental laws of physics and chemistry, to describe the formation mechanism of protective coatings by the micro-arc oxidation method taking into account the large number of physical effects inherent in this process is proposed. The proposed model can be used to increase the controllability of micro-arc oxidation technology.
Solid-state phase transition of tetracosane C24H50
Authors: Gureva S A , Borisov A K , Marikhin V A , Egorov V M 
Published: December 2020

Abstract
The heterogeneous structural phase transition in the even n-alkane tetracosane C24H50 was studied by IR spectroscopy and DSC. It was found that the initial nanonuclei of the hexagonal phase are formed in the lamellas cores and their volume was calculated.
Study of long-term post-SHS phase kinetics in Ni/Al reactive multilayer nanofoils
Authors: Kvashenkina O E , Udovenko S A , Osipov V S , Gabdullin P G , Bisyaev I S , Babyuk V Ye , Burkovsky R G , Arkhipov A V 
Published: December 2020

Abstract
We present the results of the recent experiments with two species of Ni/Al reactive multilayer nanofoils (RNMFs) supporting the self-propagating high-temperature synthesis (SHS) reaction. SEM method was used to evaluate their general structure and quantitative chemical composition before and after reaction. Phase composition was determined from XRD spectra. Special attention was paid to the stability of phase composition over relatively long time intervals after SHS reaction – order of the hours and days. In some cases, XRD spectra showed notable evolution of crystalline structure, which can have significant impact on practical application of SHS, for instance, in soldering technologies. To our knowledge, similar effect has been previously observed only for SHS-reactive powder mixtures.
The effect of low-energy ion bombardment on residual stress in thin metal films due to the generation of surface defects and their migration to the grain boundary
Authors: Babushkin A S 
Published: December 2020

Abstract
A kinetic model that describes the evolution of residual stress in thin polycrystalline films during bombardment by ions with energies below the sputtering threshold is presented. The mechanisms responsible for the change in stress are the generation of point defects on the surface and their redistribution over the film thickness along grain boundaries. The presented model was used to explain the experimental data on the change in stress in thin Cr films after treatment in Ar plasma of low-pressure RF induction discharge with ion energy of 15-30 eV.
Application of the Atomic Layer Etching technique to remove broken layers after plasma-etched GaAs surface treatment
Authors: Klimin V S , Rezvan A A , Abramovich T S , Zubova T A , Tominov R V , Vakulov Z E , Kots I N , Ageev O A 
Published: December 2020

Abstract
The work considers the application of focused ion beam techniques for the formation of nanoscale structures, as well as the atomic layer etching method for removing layers with surface defects. Also in the work, modeling of the formation of structures by the FIB method on the GaAs surface was used to determine the depth of penetration of atoms into the structure under certain experimental conditions. This method of forming defect-free structures was developed for the formation of a nanoscale surface relief for the subsequent growth of quantum dots by the method of drop molecular beam epitaxial.
Method for analyzing the electrophysical properties of semiconductor quantum dots
Authors: Mikhailov A I , Kabanov V F , Gavrikov M V 
Published: December 2020

Abstract
Some important properties of the InSb and CdSe quantum dots, such as size and energy spectrum, were studied by method of normalized differential tunneling current-voltage characteristics. The results of size evaluation are qualitatively and quantitatively consistent with the results obtained by TEM and analysis of spectral dependence of absorption coefficient and luminescence with an error less than 15%. During the study it was also shown, that method of normalized differential tunneling current-voltage characteristics also allows us to analyze the energy spectrum of semiconductor quantum dots (position of the first three energy levels).
Multiply GaAs quantum dots in AlGaAs nanowires: MBE growth and properties
Authors: Reznik R R , Kotlyar K P , Khrebtov A I , Samsonenko Yu B , Shtrom I V , Cirlin G E 
Published: December 2020

Abstract
A possibility of the AlGaAs nanowires with multiply GaAs QDs MBE growth on silicon substrates has been demonstrated. The morphological on optical properties of grown structures were studied.