2304-9782, 2618-8686, 2405-7223 17 3.1 2024 1-372

CNF RUS 10-13 Moscow Institute of Physics and Technology (National Research University) Patarashvili Anton patarashvili@phystech.edu

Moscow, Russian Federation

Moscow Institute of Physics and Technology (National Research University) Efimov Alexey efimov.aa@mipt.ru

Dolgoprudny, Moscow region, Russian Federation

Moscow Institute of Physics and Technology (National Research University) Ivanov Mattew ms.ivanov@phystech.edu

Dolgoprudny, Moscow region, Russian Federation

Ghorbani Fard Mohammad Reza 0009-0005-1810-956X Maslennikov Dmitry Ivanov Victor ivanov.vv@mipt.ru Effect of the electrostatic focusing lens voltage on structures size in 3D printing by charged Au nanoparticles The paper demonstrates a method for three-dimensional aerosol printing of charged nanoparticles using electrostatic focusing through a conductive matrix lens. The study showcases the successful printing of narrow and highly conductive structures on a silicon substrate, utilizing 20–180 nm gold nanoparticles and alternating voltage on a stainless-steel lens. The results indicate that structures significantly smaller than the lens holes were achieved, and an experimental relationship between the structure width and lens voltage was established. 10.18721/JPM.173.101 537.533.331 focusing nanoparticles microstructure inkjet printing aerosol charging additive manufacturing https://physmath.spbstu.ru/article/2024.75.1/

CNF RUS 14-18 0009-0005-0242-4784 Ivanov Vladimir vladimir.ivanov@metalab.ifmo.ru 0000-0002-9381-9650 Sapori Daniel Development of semitransparent Perovskite Solar Cells with double electron transport layer and modified top electrode In this work we report on semitransparent perovskite solar cell fabrication using double electron transport layer and double top electrode. Such devices may be used in tandem solar cells which are made to overcome Shockley-Queisser limit for one junction solar cell and improve efficiency of the device. One of the main issues of this task is to make transparent top electrode since it is usually made of metal. In this work the combination of ITO/Ag is used in which silver is deposited via special mask to improve conductivity. Top ITO electrode was deposited via magnetron sputtering – the process was optimized for room temperatures to avoid perovskite and organic degradation. ZnO nanoparticles are incorporated in device as second electron transport layer to protect all below layers from ITO sputtering damage. This layer was deposited via spin-coating process, which is much easier and faster than atomic layer deposition, which is usually used for ZnO deposition. The best semitransparent perovskite solar cell made with these modifications showed 11.5% efficiency with high VOC value of 1.1 V. 10.18721/JPM.173.102 538.9 Perovskite solar cells photovoltaics tandem solar cells semitransparent electrode double electron transport layer https://physmath.spbstu.ru/article/2024.75.2/

CNF RUS 19-22 Morozova Ekaterina morozovaev@ulsu.ru Timkaeva Diana dianatimkaeva@mail.ru Thermal and electrical conductivity of grain boundaries in metals with bcc and fcc crystal lattices This study employs first-principles calculation methods to investigate the thermoelectric properties of high-angle grain boundaries in metals (iron, titanium, copper, and nickel) with symmetric tilt boundaries of two types of crystal  lattice: body-centered cubic and face-centered cubic. Grain boundaries play a significant role in carrier and phonon transport in materials. Altering geometric parameters is one of the simplest ways to control thermoelectric characteristics. By varying the grain rotation axis, rotation angle, and grain self-orientation, we derived the dependence of the electrical and thermal conductivity of studied materials on the geometry of the modeled device at room  temperature. The results presented in the work can give an idea of the effect of this type of surface defect on thermal and electrical conductivity. 10.18721/JPM.173.103 29.19.22 grain boundary electrical conductivity thermal conductivity https://physmath.spbstu.ru/article/2024.75.3/

CNF RUS 23-27 0000-0002-1405-5745 Seredin Boris 0000-0001-6561-4319 Popov Victor 0000-0001-9534-2246 Malibashev Alexander 0009-0008-9843-6553 Stepchenko Artem The effect of the rate of temperature change on the thermomigration of liquid inclusions in silicon The influence of the rate of temperature change of the composition on the consistency of the processes of dissolution, crystallization and atomic transfer in a liquid inclusion and at its boundaries, characteristic of stationary  conditions of thermomigration, is theoretically estimated. Using the example of the silicon-aluminum system, the effect of stepwise and smooth temperature changes on the processes determining thermal migration and the velocity of  movement of the liquid inclusion is established. A critical rate of temperature change has been found, above which thermomigration becomes impossible. 10.18721/JPM.173.104 621.315.592.3 thermomigration silicon crystallization dissolution https://physmath.spbstu.ru/article/2024.75.4/

CNF RUS 28-33 Shandyba Nikita shandyba.nikita@gmail.com Eremenko Mikhail eryomenko@sfedu.ru Alferov University Sharov Vladislav vl_sharov@mail.ru

St. Petersburg, Russian Federation

Balakirev Sergey sbalakirev@sfedu.ru Solodovnik Maxim solodovnikms@sfedu.ru Control of properties and geometric characteristics of selectively formed GaAs nanowires within the FIB treatment area on Si(111) In this paper we present the results of experimental studies on the selective formation of GaAs nanowire arrays on the Si(111) substrate surface and the control of their properties. It has been shown that pre-treatment of the Si(111)  surface with a native oxide layer by a focused Ga-ion beam with further low-temperature annealing and high-temperature growth allows the formation of selective GaAs nanowire arrays with a different set of parameters that can be  controlled by changing the dose of ion-beam treatment. We also demonstrated the possibility of obtaining arrays with a yield of vertically oriented nanowires at the level of almost 100% and very high density (up to 8 μm−2). At the  same time outside the modified areas, the formation of nanowires was almost completely suppressed. Moreover, based on Raman spectroscopy study we have found that our approach allows to obtain nanowire arrays with clear zinc-blende crystal phase in wide range of nanostructure sizes. 10.18721/JPM.173.105 538.975 nanowires gallium arsenide focused ion beam molecular beam epitaxy A3B5 https://physmath.spbstu.ru/article/2024.75.5/

CNF RUS 34-37 0000-0002-4513-6345 Ruzhevich Maxim max.ruzhevich@niuitmo.ru Mynbaev Karim mynkad@mail.ioffe.ru Bazhenov Nikolai bazhnil.ivom@mail.ioffe.ru 0000-0002-3640-677X Ioffe Institute Kaveev Andrey kaveev@mail.ioffe.ru

St. Petersburg, Russian Federation

Peter the Great St. Petersburg Polytechnic University Pavlov Alexander a.pavlov@physics.spbstu.ru 0000-0001-5547-9387 Alferov University Fedorov Vladimir fedorov_vv@spbstu.ru 0000-0001-9792-045X Peter the Great St. Petersburg Polytechnic University Mukhin Ivan muhin_is@spbstu.ru Photoluminescence of self-induced InAs nanowires diluted with nitrogen Photoluminescence of arrays of self-induced nanowires consisting of pure InAs and of InAs diluted with nitrogen was studied in the 4.2–300 K temperature range. Formation of the hexagonal wurtzite (nanowires) and cubic sphalerite  (mostly parasitic islands) crystal structure modifications was observed on a Si substrate used for the growth of the nanowires. A decrease in the band gap of both crystalline phases due to the introduction of nitrogen was established. 10.18721/JPM.173.106 538.958; 538.975 InAs nanowires photoluminescence crystal structure https://physmath.spbstu.ru/article/2024.75.6/

CNF RUS 38-42 Chernenko Natalia nchernenko@sfedu.ru National Research University ‘Higher School of Economics” Makhov Ivan imahov@hse.ru Melnichenko Ivan imelnichenko@hse.ru 0009-0003-3518-8402 Yakunina Ksenia iakunina@sfedu.ru Balakirev Sergey sbalakirev@sfedu.ru Kryzhanovskaya Natalia V. Natalia nkryzhanovskaya@hse.ru Solodovnik Maxim solodovnikms@sfedu.ru Quantum dots formation by InGaAs decomposition onto a patterned GaAs surface In this work, we present the results of experimental studies of the formation processes and optical properties of ordered arrays of InGaAs nanostructures obtained by deposition of quantum well material layer on the nanopatterned  GaAs surface. For GaAs nanopatterning we used our original technique based on the combination of focused ion beam treatment and local droplet etching which allows to create regular arrays of nanoholes with different  morphology. Using room-temperature photoluminescence (PL) intensity mapping we have shown that quantum well material localizes inside the created holes but position of corresponding PL peak (960–970 nm) is independent of  morphology and is determined only by the chemical composition of the deposited material. Based on low-temperature (5 K) PL measurements we conclude that inside the holes quantum well decomposes due to the difference in a  mobility of Ga and In adatoms during its material deposition with formation a “quantum well + quantum dot” system. While the quantum well PL peak locates approximately at 920 nm, the quantum dot lines lie in the wavelength range  of 930–950 nm. 10.18721/JPM.173.107 538.9 quantum dots A3B5 decomposition structuring molecular beam epitaxy nanostructures nanopatterning https://physmath.spbstu.ru/article/2024.75.7/

CNF RUS 43-46 Belov Yaroslav yadbelov@gmail.com Zimin Sergey zimin@uniyar.ac.ru Amirov Ildar ildamirov@yandex.ru Mazaletsky Leonid boolvinkl@ya.ru Формирование наноконусов на поверхности пленок Pb0.4Sn0.6Te при ионно-плазменной обработке ионами аргона с энергией 140 эВ The article studies the modification of the surface of Pb0.4Sn0.6Te epitaxial films during ion-plasma treatment in argon plasma. Lead-tin telluride films with a thickness of 2 μm were grown on BaF2 (111) substrates by molecular beam epitaxy. Ion-plasma treatment was carried out in a dense argon plasma of a high-frequency inductive discharge at an ion energy of ~140 eV. The duration of the process is 60 and 120 s. The parameters of an ensemble of nanocones are studied, the evolution of the height of the cones, their lateral dimensions and surface density is described while maintaining the processing time. 10.18721/JPM.173.108 533.924 аргоновая плазма теллурид свинца-олова наноструктурирование https://physmath.spbstu.ru/article/2024.75.8/

CNF RUS 47-51 0009-0007-3942-7908 Kan Gennadiy gennadiykang@gmail.com Alferov University Reshetov Ilya reshetov_iv@spbstu.ru 0000-0002-1744-5976 Terpitskiy Aleksey Alferov University Scherbak Sergey sergeygtn@yandex.ru Alferov University Lipovskii Andrey lipovskii@mail.ru Ion exchange method for obtaining second-order nonlinearity in glass In this work, we propose two-step process to create a second-order nonlinearity in glasses. First, we use the ion exchange method to form a region of an ion concentration and, consequently, conductivity gradient in glass.  Afterwards, we apply DC voltage to the specimen at room temperature. This causes formation of non-equilibrium charge and inner electrostatic field, which induces effective second-order optical nonlinearity of the glass that exceeds  one of thermally poled glass sample. After turning the voltage off, the effect gradually degrades within a few hundreds of seconds. Comparison of silver-for-sodium and potassium-for-sodium ion exchanges shows that in the latter  case the result nonlinearity has longer relaxation time. 10.18721/JPM.173.109 535.016 glass ion-exchange Maxwell-Wagner effect EFISH second harmonic generation https://physmath.spbstu.ru/article/2024.75.9/

CNF RUS 52-57 0000-0001-8222-8030 Stanchik Aliona alena.stanchik@bk.ru 0000-0001-9920-8159 Buskis Konstantin 0000-0002-3442-5299 Gremenok Valery Kabyliatski Aliaksandr Khoroshko Vitaliy Zimin Sergey zimin@uniyar.ac.ru Amirov Ildar ildamirov@yandex.ru Quantum size effect in cadmium sulphide films after plasma treatment In this work, the optical properties of nanocrystalline CdS films in the initial state and after ion-plasma treatment have been studied. The chemical bath deposition technique was used to prepare CdS films with thickness 80–115 nm on glass substrates. The ion-plasma treatment was carried out in argon plasma in a high-density low-pressure radio frequency inductively coupled plasma reactor at an argon ion energy of 25 eV for 30–50 s. It has been established  that ion-plasma treatment leads to a decrease in film thickness by 10–15% of the initial one and the formation of new nanostructures on its surface. The results showed that the sizes of coherent scattering regions during plasma  treatment decreased for a series of studied samples from 8.2–10.0 nm to 6.3–7.7 nm. This led to an increase in the band gap energy of the for nanocrystalline CdS films from 2.53–2.78 eV to 2.95–3.11 eV. 10.18721/JPM.173.110 538.958, 54.057 cadmium sulphide thin films chemical bath deposition plasma treatment transmission spectra band gap energy https://physmath.spbstu.ru/article/2024.75.10/

CNF RUS 58-62 Lakhina Ekaterina lakhina@sfedu.ru Chernenko Natalia nchernenko@sfedu.ru Shandyba Nikita shandyba.nikita@gmail.com Kirichenko Danil dankir@sfedu.ru Balakirev Sergey sbalakirev@sfedu.ru Solodovnik Maxim solodovnikms@sfedu.ru Influence of annealing conditions on the characteristics of nanoholes formed by focused ion beams on the GaAs(111) surface In this paper, we study the effect of annealing of GaAs(111) substrates under various conditions on the morphological characteristics of nanoholes formed by focused ion beams. In the absence of annealing and when annealing in  the absence of the arsenic flux, the depth and lateral size of nanoholes increase with the number of ion beam passes. In the case of annealing of the substrates in the arsenic flux, the dependences of the hole depth and lateral size  on the number of beam passes is non-monotonic, which is attributed to the competition of the processes of surface etching by gallium droplets during thermal oxide removal and droplet crystallization in the arsenic flux. We demonstrate technological conditions enabling formation of highly symmetric nanoholes in the form of triangular pyramids. 10.18721/JPM.173.111 538.9. focused ion beams annealing local droplet etching GaAs(111) https://physmath.spbstu.ru/article/2024.75.11/

CNF RUS 63-67 0009-0008-4344-4863 Alferov University Nikolaeva Aleksandra

St. Petersburg, Russian Federation

0000-0002-3469-5897 Alferov University Kondratev Valeriy kvm_96@mail.ru

St. Petersburg, Russian Federation

Kadinskaya Svetlana skadinskaya@bk.ru 0009-0007-9013-7973 Kolesina Diana Zubov Fedor fzubov@hse.ru 0000-0002-2209-6483 Alferov University Kochetkov Fedor

St. Petersburg, Russian Federation

0000-0002-4172-940X Alferov University Dvoretckaia Liliya Lendyashova Vera erilerican@gmail.com Gridchin Vladislav gridchinvo@gmail.com 0009-0009-7051-8458 Alferov University Monastyrenko Anatoliy

St. Petersburg, Russian Federation

0000-0001-7223-7232 Moscow Institute of Physics and Technology (National Research University) Bolshakov Alexey acr1235@mail.ru

Moscow, Russian Federation

Pressure and temperature sensing via ZnO-PDMS based membrane for wearable electronic applications In this work, we have grown vertically oriented ZnO microstructures via low-temperature hydrothermal method using microsphere photolithography and followed by etching to prepare the growth substrate and establish ZnO nucleation  areas. The synthesized structures were rod-shaped ZnO microcrystals with a height of 5 μm and a diameter of about 400 nm. Such structures were encapsulated in polydimethylsiloxane (PDMS) for ZnO-PDMS membrane  formation. Based on this membrane, flexible and solid pressure sensors were fabricated. All sensors have been studied using electrical impedance spectroscopy in terms of the change in resistance and electrical capacitance when  pressure is applied. A correlation between the electrical characteristics of such sensors and an applied mechanical pressure was demonstrated. One of such sensors shows the possibility of synchronous measurement of pressure  and temperatures in the range of 25 °C – 100 °C was demonstrated. Fabricated sensors can find their application in the field of personalized healthcare and for the advancement of electronic skin (E-skin). 10.18721/JPM.173.112 538.9 ZnO PDMS sensor https://physmath.spbstu.ru/article/2024.75.12/

CNF RUS 68-74 Romashkin Alexey romaleval@gmail.com 0000-0001-5063-1669 Rozanov Roman Lashkov Andrey lav.lab-sm.sstu@rambler.ru 0000-0002-4024-5411 Vishnevskiy Alexey Mitrofanova Anastasia mitrofanova.ae@phystech.edu Levin Denis vkn@miee.ru Svetikov Vladimir vl.svetikov@gmail.com Change in the carbon nanotube thin layer refractive index after water and ammonia molecules adsorption Spray-deposited carboxylated carbon nanotube (CNT) layers were characterized using AFM, Raman, and spectroscopic ellipsometry. The layers’ thickness, diameters and band gap of CNTs, as well as the changes in the CNT layer  refractive index at 1319 nm and 2010 nm after H2O and NH3 adsorption in air and H2O in N2 were analyzed. Refractive index changes and modeling the necessary length of the modified interferometer arm for a π/2 phase shift allow  us to propose the use of such CNT layers for integrated interferometric sensors and gas recognition. 10.18721/JPM.173.113 [621.793+544.164]::681.787.22 carbon nanotube ellipsometry integrated optics interferometer sensor https://physmath.spbstu.ru/article/2024.75.13/

CNF RUS 75-78 Eremenko Mikhail eryomenko@sfedu.ru Shandyba Nikita shandyba.nikita@gmail.com Chernenko Natalia nchernenko@sfedu.ru Southern Federal University Jityaeva Julia zhityaeva@sfedu.ru

Taganrog, Russian Federation

Balakirev Sergey sbalakirev@sfedu.ru Solodovnik Maxim solodovnikms@sfedu.ru Combined approach of patterning on SiO2/Si substrate using ion beam and chemical wet etching In this work, we studied the influence of combined processing of SiO2/Si(001) substrates using focused ion beams (FIB) and wet chemical etching on the possibility of forming pyramidal cavities and their geometric parameters. It has  been shown that etching FIB-modified samples only in KOH leads to the formation of pyramidal cavities covered with a shell, possibly made of porous silicon layer. We have shown that the use of an isotropic etchant before  anisotropic etching allows to remove a porous silicon layer. An increase in the implantation dose led not only to an increase in the depth of the cavities, but also to an increase in the undercut of the oxide layer. 10.18721/JPM.173.114 538.9 wet chemical etching silicon monolithic integration focused ion beam nanopatterning https://physmath.spbstu.ru/article/2024.75.14/

CNF RUS 79-83 Kirichenko Danil dankir@sfedu.ru National Research University ‘Higher School of Economics” Makhov Ivan imahov@hse.ru Balakirev Sergey sbalakirev@sfedu.ru Kryzhanovskaya Natalia V. Natalia nkryzhanovskaya@hse.ru Solodovnik Maxim solodovnikms@sfedu.ru Study of the photoluminescence properties of subcritical InAs/GaAs quantum dots formed onto structured substrates In this work we study the optical properties of InAs quantum dots grown on the GaAs(001) nanostructured surfaces at sub-critical thickness of deposition. For substrate nanostructuring we used technique based on two-stage thermal  desorption of native GaAs oxide under molecular arsenic flux. The results of experimental studies showed the possibility of quantum dots formation on structured surfaces at equivalent deposition thicknesses in the range of 0.5–1.5  ML. In this case, quantum dots are formed predominantly in nanoholes on the surface and are high inhomogeneous in size. At the same time measurements by photoluminescence spectroscopy showed broad (900–1100 nm)  emission spectrum for quantum dot only for sample with 1.5 ML of InAs. We hypothesize that at smaller thicknesses, the formed quantum dots become smaller than the minimum acceptable sizes due to segregation effects during  overgrowth. The use of a structured surface also makes it possible to suppress the wetting layer formation – in the photoluminescence spectra there are only lines of platelets, apparently formed on morphological inhomogeneities  outside the holes. 10.18721/JPM.173.115 538.9 native oxide quantum dots A3B5 molecular beam epitaxy nanopatterning https://physmath.spbstu.ru/article/2024.75.15/

CNF RUS 84-88 0009-0002-2923-804X Gajna Anna gajna.aa@edu.spbstu.ru Mozhayko Anna annaanna-1996@mail.ru Davydov Vadim davydov_vadim66@mail.ru Modeling of the scanning track formation in the selective laser melting process of 316L steel Selective laser melting (SLM) is a promising additive manufacturing method that uses metal powder materials and heats them with a laser beam to the melting temperature in such a way that the metal powder layer completely melts.  This paper presents a study of SLM process for austenitic 316L steel. The study focuses on single laser track formation and the effects of laser radiation parameters on melt pool size. The research aims to investigate the effects of  various laser radiation parameters on the melt pool dimensions in a sample. These parameters include laser power, scanning speed, and laser focal spot diameter. A computational model, created using the COMSOL Multiphysics  finite element software, is used to simulate the behavior of the sample under different processing conditions and determine the optimal processing parameters. Results show that the melt width, length and depth depend on above  laser parameters. This research contributes to our understanding of SLM processes and provides valuable insights into optimizing processing parameters for achieving desired sample properties. 10.18721/JPM.173.116 536.331; 536.421.5 selective laser melting heat transfer modeling finite element method austenitic steel melt pool https://physmath.spbstu.ru/article/2024.75.16/

CNF RUS 89-94 0000-0001-7499-0578 Institute of High Current Electronics, Siberian Branch of RAS Kozhevnikov Vasily Vasily.Y.Kozhevnikov@ieee.org Kozyrev Andrey kozyrev@to.hcei.tsc.ru Kokovin Aleksandr alexander.kokovin.desch@gmail.com The role of ectons in the vacuum breakdown process This paper presents a valuable addition to the kinetic theory regarding vacuum breakdown formation in a planar vacuum gap, specifically focusing on the cathode plasma emission known as the 'ectonic' (pulse-periodic quasi-particle)  nature. We investigate the contributions of ectonic and continuous types of emission from the cathode in terms of their effects on the mechanism of anomalous ion acceleration and cathode plasma expansion during a short-term switching of the emission current corresponding to the death and birth of ectons. 10.18721/JPM.173.117 533.9.02 vacuum breakdown Vlasov-Poisson equations ectons https://physmath.spbstu.ru/article/2024.75.17/

CNF RUS 95-99 Levin Alexis levin.alescha2013@yandex.ru Pecherskaya Ekaterina pea1@list.ru 0000-0001-5075-2727 Penza State University Shepeleva Juliya

Penza, Russian Federation

Antipenko Vladimir v.antipenko7@yandex.ru Yakushov Dmitriy hammer.fate@yandex.ru 0000-0002-3240-7222 Penza State University Artamonov Dmitriy dmitrartamon@yandex.ru

Penza, Russian Federation

Options for implementing electrical impedance tomography for diagnostics blood clots and bruises The possibility of detecting and diagnosing bruises, blockages of veins or arteries and blood clots based on electroimpedance tomography is being considered. The advantages of electroimpedance tomography compared to other  similar methods are substantiated. Physical principles are presented, implementation options for the electrical impedance tomography method are systematized; the basics of the clinical application of this diagnostic method including the capabilities of both classical and portable installation options are outlined. 10.18721/JPM.173.118 616-71 еlectroimpedance tomography non-invasive diagnosis bioimpedance biological tissue electrode https://physmath.spbstu.ru/article/2024.75.18/

CNF RUS 100-104 0000-0002-6762-2053 Southern Federal University Dukhan Denis duhan@sfedu.ru

Taganrog, Russian Federation

Balakirev Sergey sbalakirev@sfedu.ru 0000-0002-1799-1125 Shanghai University Voloshina Elena

Shanghai, China

Solodovnik Maxim solodovnikms@sfedu.ru Ab initio study of In adsorption on AlxGa1–xAs substrates at the first stages of droplet epitaxy In this work we study the adsorption of In on AlxGa1–xAs substrates at the first stage of droplet epitaxy with goal of explaining the anomalous behavior observed in previous experiments where an increase in the content of chemically  active Al in AlxGa1–xAs substrates led to an increase in the surface mobility of In adatoms affecting the final distribution of InAs quantum dots. DFT simulations showed that when In adatoms directly interact with As-terminated substrates, there is no deviation from normal behavior, but when In binds with a fully formed In wetting layer, the results are in agreement with those observed in our experiments – increasing Al content led to a decrease in adsorption  energy, which means that surface mobility of adatoms has increased. We assume that this specific effect of droplet epitaxy is caused by lack of a stabilizing As layer, allowing the formation of In dimer rows and direct  interaction of adatoms with them. 10.18721/JPM.173.119 538.9 density functional theory III-V indium surface mobility quantum dots droplet epitaxy molecular beam epitaxy https://physmath.spbstu.ru/article/2024.75.19/

CNF RUS 105-109 Pleninger Maximilian pleninger@sfedu.ru Balakirev Sergey sbalakirev@sfedu.ru Solodovnik Maxim solodovnikms@sfedu.ru Simulation of an all-optical logical comparator based on a GaAs photonic crystal operating at a wavelength of 1.3 μm This paper presents the results of simulation of a compact all-optical logical comparator based on a GaAs photonic crystal. The influence of geometric parameters of structural elements of the photonic crystal on characteristics of the  comparator was studied in order to establish the optimal diameter of GaAs columns and the distance between them (period) for operation at a wavelength of 1.3 μm. Simulations of the dependences of the ratio of signal intensities at the input and output of the comparator show that it decreases with increasing diameter, both with one and both open channels. Calculating the difference between these ratios, we reveal that an optimal diameter of the  photonic crystal columns is equal to 155 nm. After a similar study for the distance between the GaAs columns, we determine its optimal value as 600 nm. 10.18721/JPM.173.120 537.876 photonic crystal logical comparator GaAs https://physmath.spbstu.ru/article/2024.75.20/

CNF RUS 110-114 0000-0002-3469-5897 Alferov University Kondratev Valeriy kvm_96@mail.ru

St. Petersburg, Russian Federation

0000-0001-7143-6686 Kusnetsov Alexey alkuznetsov1998@gmail.com 0009-0003-5049-538X Alferov University Zavyalova Eseniya

St. Petersburg, Russian Federation

Anikina Maria mari.a.nikina@yandex.ru 0000-0001-7223-7232 Moscow Institute of Physics and Technology (National Research University) Bolshakov Alexey acr1235@mail.ru

Moscow, Russian Federation

Resonant scattering of silicon nanopillars for nonlinear optics This article summarizes the findings of a study on resonant scattering from single silicon nanopillars on a native substrate in the visible and near infrared spectral ranges. The study utilizes numerical simulation finite-difference time- domain method to investigate the effects of lateral and vertical dimensions of the pillars on their scattering behavior. The results show that manipulating the dimensions can shift resonance modes and enhance scattering intensity. Various pillars design variations are explored, including different lengths and radii, with the aim of optimizing scattering intensity for up-conversion devices. 10.18721/JPM.173.121 535 resonant scattering silicon pillars nonlinear optics https://physmath.spbstu.ru/article/2024.75.21/

CNF RUS 115-119 0009-0000-3147-6974 Alferov University of RAS Funtikova Anastasiia 0000-0002-8661-4083 Alferov University Mozharov Alexey mozharov@spbau.ru

St. Petersburg, Russian Federation

0000-0001-5547-9387 Alferov University Fedorov Vladimir fedorov_vv@spbstu.ru Alferov University Sharov Vladislav vl_sharov@mail.ru

St. Petersburg, Russian Federation

0000-0001-9792-045X Peter the Great St. Petersburg Polytechnic University Mukhin Ivan muhin_is@spbstu.ru Numerical modal analysis of GaP optical microcavity Despite the highly developed level of the silicon technology, efficiency of silicon-based photon devices is limited by material properties. In contrast, III-V materials are mostly applicable to make such type of devices as well as  fabricating them in nanowire (NW) form provides compatibility with silicon technology. GaP(NAs) is a useful material system for optoelectronics because of tunable bandgap with controllable directivity and high refractive index. The  eigenmodes of the Fabry-Perot resonator based on GaP NWs have been investigated. The simulation results showed that raise in diameter leads to the increase in the number of optical modes having different light distribution due  to transverse mode type. Quality factor analysis shows growth in its values with the increase in structures’ diameters. 10.18721/JPM.173.122 535.3 nanowires gallium phosphide Fabry-Perot resonance waveguide modes https://physmath.spbstu.ru/article/2024.75.22/

CNF RUS 120-123 0000-0001-9319-2475 Research Institute of Electronic and Mechanical Devices Novichkov Maksim

Penza, Russian Federation

0000-0001-9602-7221 Research Institute of Electronic and Mechanical Devices Gurin Sergey

Penza, Russian Federation

Shepeleva Anastasia eduard.shepelev.67@mail.ru Pecherskaya Ekaterina pea1@list.ru 0009-0009-4548-3724 Agafonov Dmitriy Ilyin Vitaly Nanostructured bimetallic PtNi catalyst for electrochemical systems with solid polymer electrolyte A method for forming a nanostructured bimetallic PtNi catalyst on the surface of a solid polymer electrolyte is presented. Nickel particles, on which the bulk of the platinum catalyst is grown by chemical deposition, are obtained by  magnetron sputtering. The resulting system has high catalytic activity and temporary stability. 10.18721/JPM.173.123 544.478-03 bimetallic catalyst solid polymer electrolyte catalytic layer magnetron sputtering chemical deposition https://physmath.spbstu.ru/article/2024.75.23/

CNF RUS 124-128 Alferov University Reshetov Ilya reshetov_iv@spbstu.ru Peter the Great St. Petersburg Polytechnic University Babich Ekaterina babich.katherina@gmail.com Alferov University Lipovskii Andrey lipovskii@mail.ru 0000-0003-3741-3936 Ioffe Physical Technical Institute of the Russian Academy of Sciences Melehin Vladimir melekhin1952@gmail.com Nashchekin Alexey V. nashchekin@mail.ioffe.ru Formation of silver nanoparticles in glass by vacuum thermal poling It is shown that the vacuum poling of soda-lime silicate glass followed by silverfor-sodium ion exchange results in the formation of silver nanoparticles (NPs) in subcathode region of the glass. The latter was confirmed by the presence of silver NPs’ localized surface plasmon resonance peak in optical absorption spectra of the samples. The NPs had grown in 2 μm thick subsurface region of the glass, which was confirmed by etching the cathode side of the sample.  The possibility of forming a 2D-structured pattern from silver NPs that repeats the relief of the cathode electrode used for poling, has also been demonstrated. A hypothesis about the reduction of silver ions during the ion exchange  by sodium atoms penetrated the glass from the cathode during poling in vacuum is proposed. 10.18721/JPM.173.124 537.5 soda-lime glass thermal poling silver nanoparticles https://physmath.spbstu.ru/article/2024.75.24/

CNF RUS 129-133 Ershov Evgenii Fomin Alexey dep5@vniitf.ru Lupachev Maksim Dep5@vniitf.ru Rogachkov Oleg Naidin Andrei Heterostructure design features for 975 nm high-power laser diodes The heterostructure design has been optimized to achieve high radiation output power and high conversion efficiency of 970–980 nm laser diodes. The influence of active layer geometry and waveguide layer doping on the output  electrical and optical LD chip parameters has been studied. As a result of the optimization, operating LD output of 11.6 W has been achieved at a current of 12 A. The maximum conversion efficiency was 65% at a pump current of  5A. 10.18721/JPM.173.125 621.315.529 laser diode laser cavity heterostructure quantum well https://physmath.spbstu.ru/article/2024.75.25/

CNF RUS 134-137 0009-0005-9558-4583 Yarchuk Ernst 0000-0001-6869-1213 Alferov University Vyacheslavova Ekaterina cate.viacheslavova@yandex.ru 0009-0009-7051-8458 Alferov University Monastyrenko Anatoliy

St. Petersburg, Russian Federation

0000-0002-7632-3194 Alferov University Gudovskikh Alexander gudovskikh@spbau.ru Effect of light incidence angle on the characteristics of silicon solar cells with different texturing The influence of the angle of incidence of the light flux on the photovoltaic performance of two types a-Si:H/c-Si heterojunction solar cells is investigated: KOH textured with a pyramidal surface, and black silicon with a nanostructured  surface. Current-voltage characteristics and power depending on the angle of incidence of the solar flux – from 14 mW/cm2 to 3 mW/cm2 for pyramidal surface and from 9 mW/cm2 to 2 mW/cm2 for black silicon in the angle range 0–75° were obtained. Solar cell based on black silicon retains its characteristics 6% better as the angle of incidence of light increases to 75°. 10.18721/JPM173.126 621.311.243 black silicon amorphous silicon heterojunction solar cell current-voltage characteristic angle of incidence https://physmath.spbstu.ru/article/2024.75.26/

CNF RUS 138-141 Perm State University Pankov Anatoliy lab.photon.psu@gmail.com

Perm, Russian Federation

0000-0001-9729-628X Perm State University Ponomarev Roman rsponomarev@gmail.com

Perm, Russian Federation

Microlenses formation by electric arc at the end of optical fibres, preserving the polarization of optical radiation In this paper, the use of tapered optical fibers with preservation of radiation polarization for the fabrication of microlenses is considered. The contraction of the fibers is achieved by stretching optical fiber under the influence of the  electric arc the splicing machine. This method allows to fabricate microlenses with a mode field diameter at the focal point of up to 2 μm and with a polarization extinction ratio (PER) coefficient of radiation at the output of the microlens of up to 40 dB. At the same time, the drop in the PER coefficient in the microlens is no more than 3 dB. 10.18721/JPM.173.127 681.7.068 fiber microlens tapered fiber fiber with preservation of polarization polarization extinction ratio focal length mode field diameter https://physmath.spbstu.ru/article/2024.75.27/

CNF RUS 142-146 Penza State University Golubkov Pavel golpavpnz@yandex.ru

Penza, Russian Federation

Pecherskaya Ekaterina pea1@list.ru Yakushov Dmitriy hammer.fate@yandex.ru Shepeleva Anastasia eduard.shepelev.67@mail.ru Penza State University Kozlov Gennady politeh@pnzgu.ru

Penza, Russian Federation

0000-0002-6692-1692 Pecherskiy Anatoliy Determination of the equivalent electric circuit parameters of a galvanic cell in the micro-arc oxidation process A method for determining the thickness of microarc coatings based on the use of electrochemical impedance spectroscopy during the microarc oxidation process is proposed. To obtain the studied oxide coatings, a silicate-alkaline  electrolyte was used in the following technological modes: sinusoidal electric current in the anode-cathode mode at a current density of 11 A/dm2. The frequency range of electrochemical impedance spectroscopy ranges from 20 Hz  to 2 MHz. During the study, the structure was revealed and the elements values of the electrical circuit of the galvanic cell were determined, taking into account electrochemical impedances by parametric optimization. The proposed  equivalent electrical circuit takes into account the processes of ion diffusion through the oxide layer and the imperfection of the electrical capacitance of the coating, which is due to its porous structure. A regression and correlation  analysis of the experimental data obtained was performed, during which the strong inverse correlation of the proportionality factor of the constant phase element of electrical circuit of the galvanic cell with the thickness of the formed  coatings was found. The method of indirect measurement of the thickness of oxide coatings has satisfactory accuracy and can be used for laboratory studies. With an increase in the accuracy and speed of measuring operations, industrial application of this method is also possible. The proposed galvanic cell equivalent electrical circuit can be implemented in the decision support subsystem of an intelligent microarc oxidation system. 10.18721/JPM.173.128 004.942 microarc oxidation process electrochemical impedance spectroscopy electrical substitution circuit galvanic cell parametric identification digital twin https://physmath.spbstu.ru/article/2024.75.28/

CNF RUS 147-152 0009-0004-3480-5322 Volik Artem Pecherskaya Ekaterina pea1@list.ru 0009-0009-4904-7874 Metalnikov Aleksey Penza State University Golubkov Pavel golpavpnz@yandex.ru

Penza, Russian Federation

Penza State University Kozlov Gennady politeh@pnzgu.ru

Penza, Russian Federation

0009-0000-3725-7326 Chikhrina Ulyana Digital signal processing during measurement of magnetic materials parameters The principles of digital signal processing in the form of electrical voltage, which contain the information necessary for indirect measurement of magnetic induction, magnetic field strength, magnetic permeability and other parameters  of magnetic materials are outlined. The structure of the processor module is presented, which implements the technique for measuring the parameters of magnetic materials and monitors the serviceability of the measuring  installation. An interface has been developed that allows remote control of an information-measuring system for measuring the parameters of magnetic materials. 10.18721/JPM.173.129 621.317.42 magnetic materials digital processing magnetic induction coercive force measurement processor module https://physmath.spbstu.ru/article/2024.75.29/

CNF RUS 153-156 0009-0006-2002-0959 Podoylov Igor i.podojlov@narfu.ru Kharlamova Anastasya kharlamova.anastasya2015@yandex.ru Development of an experimental device for measuring the internal stresses of single crystal diamond plates The paper presents a stand for measuring the internal stresses of monocrystalline diamond plates. The device is necessary to assess the quality of single crystal diamond plates as promising materials for quantum sensing. The use  of diamond plates in engineering and instrumentation is limited by their quality. The device under development is used to assess the quality of the diamond plate according to the internal voltage indicator. The resulting device is an  optical microscope with a modified polarizer system based on the phenomenon of double refraction and capable of detecting changes in the anisotropy coefficient of the sample under study. Also, software was developed for the  stand that allows analyzing the received data. The result of the work of the stand is a map of the internal stress distributions in the test sample. The stand was tested on monocrystalline diamond plates with various anisotropy  indicators. The results showed the effectiveness of the developed device, which recorded the internal stresses in the plates in all areas of graphitization, in places of cracks, etc. 10.18721/JPM.173.130 681.7 anisotropy polarizers internal stresses diamonds optical microscope https://physmath.spbstu.ru/article/2024.75.30/

CNF RUS 157-160 Bonch-Bruevich Saint Petersburg State University of Telecommunications Pozdnyakov Artem me022@mail.ru

St. Petersburg, Russian Federation

0000-0002-1945-1050 Bonch-Bruevich Saint Petersburg State University of Telecommunications Andreeva Elena

St. Petersburg, Russian Federation

Experimental study of a broadband optical source with hybrid amplification The possibility of jointly using concentrated erbium and distributed Raman amplifiers to obtain a broadband optical radiation source has been demonstrated experimentally. Computer modeling was carried out using the OptiSystem  program. The results of computer modeling and experimental research are in good agreement with each other. 10.18721/JPM.173.131 621.396.2 fiber-optic communication system Raman amplifier erbium amplifier optical fiber nonlinear effects https://physmath.spbstu.ru/article/2024.75.31/

CNF RUS 161-167 0009-0001-4255-1383 Penza State University Maksov Andrey

Penza, Russian Federation

0000-0001-9602-7221 Research Institute of Electronic and Mechanical Devices Gurin Sergey

Penza, Russian Federation

Penza State University Golubkov Pavel golpavpnz@yandex.ru

Penza, Russian Federation

Pecherskaya Ekaterina pea1@list.ru 0000-0001-5075-2727 Penza State University Shepeleva Juliya

Penza, Russian Federation

Methods and instruments for measuring surface morphology and mechanical parameters of oxide coatings Morphological studies of coatings were carried out on aluminum samples obtained by microarc oxidation. The sinusoidal current density in the anodic and anode-cathode modes was 15 A/dm2, and the processing time varied from  120 s to 960 s. The formation of oxide coatings occurred in a silicate-alkaline electrolyte. Studies of the surface topology and mechanical parameters of oxide coatings were carried out using an SEM, a laser profilometer and a universal electrical strength meter, which, in turn, made it possible to establish a relationship between the properties of the coatings and the sample processing time. Thus, an increase in the processing time during the micro-arc  oxidation of products made of valve group alloys leads to a complication of the surface morphology, as well as an increase in the size and number of pores. In addition, the coating roughness increases in the anode and anode-cathode modes. Electrical strength tests showed that all samples with the resulting coatings withstood a voltage of 600 V. Multifunctional coatings obtained using the developed technological modes are multilayer structures. They  consist of a base layer with excellent adhesion, an intermediate layer with porous structure and a top layer with high porosity and actively functioning surface. The changes revealed during morphological studies are characteristic of  the plasma growth model of coatings. The results of the conducted morphological studies of coatings can be implemented in the development of a digital twin of the microarc oxidation process. 10.18721/JPM.173.132 621.357.77; 620.22; 621.9.04 micro-arc oxidation digital twin surface morphology roughness electrical strength porosity https://physmath.spbstu.ru/article/2024.75.32/

CNF RUS 168-172 Pecherskaya Ekaterina pea1@list.ru Zinchenko Timur scar0243@gmail.com Zhurina Angelina gelya.zhurina@mail.ru 0000-0002-3240-7222 Penza State University Artamonov Dmitriy dmitrartamon@yandex.ru

Penza, Russian Federation

Penza State University Golubkov Pavel golpavpnz@yandex.ru

Penza, Russian Federation

Comparative analysis of the effectiveness of transparent conductive coatings based on various materials Transparent conductive oxide materials, which are used mainly as transparent electrodes, but have also found applications in optics, photonics and instrumentation. The main material used in production is indium oxide, alloyed with tin. However, indium is a rather expensive material, as well as a rare one. In this regard, the analysis of alternative materials made of transparent conductive oxide is relevant. Transparent conductive oxide materials are mainly used  as transparent electrodes, but have also found applications in optics, photonics and instrumentation. The main material used in production is indium oxide fused with tin. However, indium is a rather expensive material, as well as a  rare one. In this regard, the analysis of alternative materials made of transparent conductive oxide is relevant. The materials under consideration are gallium oxide doped with indium and antimony, tin oxide doped with fluorine and  antimony, zinc oxide doped with gallium and aluminum. The analysis of the main parameters of transparent conductive oxides is carried out, a method for evaluating the effectiveness of materials according to technical and economic  criteria is proposed. The methodology is based on the Laplace criterion, the compilation of a matrix of the effectiveness of materials. According to the proposed methodology, taking into account the target effect and the cost of  obtaining the studied films, the effectiveness of promising transparent conductive materials was evaluated. 10.18721/JPM.173.133 519.614 transparent conductive oxide indium oxide zinc oxide tin oxide effectiveness https://physmath.spbstu.ru/article/2024.75.33/

CNF RUS 173-177 Kudryashov Igor kudriashov.is@phystech.edu Shakhovoy Roman r.shakhovoy@goqrate.com Quantum state preparation with optical injection: Issue of intersymbol interference The dependence of the modulating signal on its history, which is referred in the literature to as intersymbol interference, may significantly affect the security of quantum key distribution. Here, we investigate the issue of intersymbol  interference in the context of quantum state preparation with pulsed optical injection. Both experimental and theoretical study are presented. 10.18721/JPM.173.134 621.382 quantum key distribution semiconductor lasers pulsed optical injection intersymbol interference https://physmath.spbstu.ru/article/2024.75.34/

CNF RUS 178-181 Belozerov Igor igas2580@yandex.ru Uvarov Ilia i.v.uvarov@bk.ru A compact MEMS switch for advanced radar systems MEMS switches are promising candidates for use in advanced radioelectronic systems. High RF performance combined with small size and low power consumption make them attractive for phased array antennas, aviation and space  equipment. This work presents a switch based on a tiny cantilever with a length of 50 μm. Its working characteristics are compared with the calculation results. The advantages of the switch in comparison with previously developed products are demonstrated. 10.18721/JPM.173.135 621.3 MEMS switch radar cantilever contact resistance pull-in voltage https://physmath.spbstu.ru/article/2024.75.35/

CNF RUS 182-185 0009-0002-0656-8433 Lazdin Ilya Kondrateva Anastasia kondrateva_n@spbau.ru Komarevtcev Ivan vanec@aport.ru Enns Yakov ennsjb@gmail.com Kazakin Aleksey keha@newmail.ru P-6861-2015 10041592700 https://orcid.org/0000-0003-2511-0188 Karaseov Platon platon.karaseov@spbstu.ru Microelectromechanical gas sensor of resistive type for detection of hydrogen sulphide low concentrations This article proposes a technology for manufacturing a microelectromechanical (MEMS) resistive gas sensor for detecting low concentrations of analytes and demonstrates the main technological characteristics of the device. MEMS  contains a silicon substrate with nickel comb electrodes that act as a microheater. The distance between the teeth on the comb is about 300 microns, and the width of the heater tracks is 100 microns. As a sensitive layer, a thin (100nm) gas-sensitive layer of nickel oxide (NiO) is applied on top of the microheaters. The operating temperature of the sensitive layer in measurement mode is 130–205 °C. All applied meters are made on a silicon membrane of  about 50 microns. The proposed work shows the effect of introducing H2S into a gas mixture from 1 to 100 ppm on the conductivity of a gas sensor. The effective operating temperature of the heating elements was determined, at  which the greatest response to the presence of hydrogen sulfide in the gas mixture is observed. 10.18721/JPM.173.136 539.8:538.975 microelectromechanical systems gas sensor nickel oxide hydrogen sulfide https://physmath.spbstu.ru/article/2024.75.36/

CNF RUS 186-190 0009-0005-3723-5924 Federal State Budgetary Institution of Science K.A. Valiev Institute of Physics and Technology of the RAS Yaroslavl Branch Morozov Matvey matvey11212@gmail.com

Yaroslavl, Russian Federation

Uvarov Ilia i.v.uvarov@bk.ru Combined resistive-capacitive MEMS switch for advanced communication systems The main characteristic of a capacitive microelectromechanical system (MEMS) switch is the ratio of capacitances in the open and closed states. In conventional switches, this ratio typically does not exceed ten and can be increased  several times by using a floating potential electrode. The dependence of the capacitive characteristics, isolation and insertion loss of a switch with the “floating” electrode on the substrate material is investigated. 10.18721/JPM.173.137 621.3 MEMS switch capacitance ratio isolation insertion loss floating potential finite element method https://physmath.spbstu.ru/article/2024.75.37/

CNF RUS 191-194 0000-0002-9806-0882 Pilipenko Kirill 0000-0002-7294-7549 Kulchenkov Evgeny 0000-0002-7746-3009 Rybalka Sergey sbrybalka@yandex.ru 0000-0002-8639-3575 Demidov Andrey Method for increasing of the voltage regulator radiation hardness For positive low-dropout linear voltage regulator the additional circuit elements have been developed in the output stage of voltage regulator, forming compensatory feedback and making it possible to increase voltage regulator  radiation hardness. 10.18721/JPM.173.138 621.382.2/.3; 537.312.54 voltage regulator total ionizing dose effects X-ray irradiation https://physmath.spbstu.ru/article/2024.75.38/

CNF RUS 195-198 0000-0002-7746-3009 Rybalka Sergey sbrybalka@yandex.ru 0000-0002-8639-3575 Demidov Andrey 0000-0002-7294-7549 Kulchenkov Evgeny 0000-0002-9806-0882 Pilipenko Kirill Radiation behaviour study of linear voltage regulator For positive low-dropout linear voltage regulator IS-LS1-3.3V it is established that the output voltage and consumption current change vary slightly in all studied total ionizing dose interval and do not fixed voltage regulator failure.  The analytical dependencies of output voltage and consumption current on the total ionizing dose have been obtained. 10.18721/JPM.173.139 621.382.2/.3; 537.312.54 total ionizing dose effects voltage regulator X-ray irradiation https://physmath.spbstu.ru/article/2024.75.39/

CNF RUS 199-203 0000-0001-6869-1213 Alferov University Vyacheslavova Ekaterina cate.viacheslavova@yandex.ru 0000-0002-0061-6687 Alferov University Uvarov Alexander lumenlight@mail.ru 0000-0002-3503-7458 St. Petersburg Electrotechnical University "LETI" Maksimova Alina A. deer.blackgreen@yandex.ru 0000-0002-4894-6503 Alferov University Baranov Artem I. baranov_art@spbau.ru

St. Petersburg, Russian Federation

0000-0002-7632-3194 Alferov University Gudovskikh Alexander gudovskikh@spbau.ru Gallium phosphide/black silicon heterojunction solar cells A new type of heterojunction solar cell based on gallium phosphide/black silicon was considered. The nanostructured surface of black silicon (b-Si) was obtained by cryogenic etching in a SF6/O2 gas mixture. The average height of  the b-Si structures varies from 1.4 to 2.1 μm. The heterojunction was fabricated by low temperature method such as plasma-enhanced atomic-layer deposition (PEALD). According to transmission electron microscopy, the thicknesses of the deposited GaP layer are fixed to be 30 nm. The layer consists of crystallites aligned along the crystal lattice direction, as well as their twins. This thin GaP layer allowed achieving a fill factor of 54.5% without transparent  conductive oxide and with a test grid. The use of GaP layer as an emitter a broadening of the external quantum efficiency spectrum boundary in the short-wavelength region. 10.18721/JPM.173.140 621.383.51 black silicon cryogenic etching gallium phosphide PEALD heterojunction solar cell https://physmath.spbstu.ru/article/2024.75.40/

CNF RUS 204-209 Kozlovskaya Ekaterina k89296190714@gmail.com 0000-0002-7012-1823 National Research University of Electronic Technology Kurbanbaeva Diana

Moscow, Russian Federation

Tsarik Konstantin tsarik_kostya@mail.ru Lashkov Andrey lav.lab-sm.sstu@rambler.ru Field plates design optimization to increase breakdown voltage of GaN HEMT This article presents the results of modeling the heterostructure of a normally-off n-channel transistor with various designs of field plates on electrodes. The use of field plates makes to possible to effectively control the distribution of  the field in the channel and increases the breakdown voltage. The optimal design parameters of field plates to achieve maximum BV were determined by study of the current-voltage characteristics, the distribution of the field in the  channel and the concentration of the majority carriers in the channel. 10.18721/JPM.173.141 621.382.323 GaN power transistor field plate breakdown voltage https://physmath.spbstu.ru/article/2024.75.41/

CNF RUS 210-214 Southern Federal University Soboleva Olga osotova@sfedu.ru

Rostov-on-Don, Russian Federation

0000-0002-8023-8283 Il`ina Marina mailina@sfedu.ru 0009-0005-0152-1486 Polyvianova Maria polyvianova@sfedu.ru Chefranov Alexander chefranov@sfedu.ru 0000-0002-1456-5139 Il`in Oleg oiilin@sfedu.ru Influence of ambient humidity on the magnitude of the piezoelectric strain coefficient of nitrogen-doped carbon nanotubes for the creation of strain sensors This paper establishes patterns of influence of ambient humidity on the piezoelectric strain coefficient and the magnitude of the current generated by nitrogen-doped carbon nanotubes (N-CNTs) during their deformation. It is shown  that at humidity up to 60%, stable current generation is observed during the deformation of N-CNTs; at higher humidity, the instability of measurements increases and the spread of the generated current grows significantly, which is  associated with a decrease in the N-CNTs piezoelectric strain coefficient. 10.18721/JPM.173.142 546.26; 537.226.86 carbon nanotubes nanopiezotronics piezoelectric response piezoelectric force microscopy atomic force microscopy https://physmath.spbstu.ru/article/2024.75.42/

CNF RUS 215-219 Popovskiy Nikita nikitanikita24@mail.ru Features of the implementation of optical superchannels in flexible optical networks This article examines the current problems of using fiber-optic communication systems for efficient long-distance data transmission. Special attention is paid to the concept of optical super channels, which combine several optical  channels to increase transmission capacity and range. The article discusses the theoretical and practical aspects of the implementation of optical superchannels, including methods for generating multichannel signals, the use of optical precompensation of nonlinear effects and dispersion, as well as technologies for multiplexing orthogonal subcarrier channels. The prospects for the development of flexible optical networks to increase productivity and optimize the use of resources in modern telecommunications networks are considered. 10.18721/JPM.173.143 535.8 flexible optical networks fiber-optic transmission system dense wavelength division multiplexing orthogonal frequency division multiplexing transceiver https://physmath.spbstu.ru/article/2024.75.43/

CNF RUS 220-223 Alferov University Sinitskaya Olesya olesia-sova@mail.ru

St. Petersburg, Russian Federation

0000-0003-1835-1629 Alferov University Shubina Kseniia rein.raus.2010@gmail.com

St. Petersburg, Russian Federation

Mokhov Dmitry mokhov@spbau.ru 0000-0002-4894-6503 Alferov University Baranov Artem I. baranov_art@spbau.ru

St. Petersburg, Russian Federation

Mizerov Andrey andreymizerov@rambler.ru Nikitina Ekaterina mail.nikitina@mail.ru GaN based ultraviolet narrowband photodetectors In this work ultraviolet metal-semiconductor-metal photodetectors with semitransparent Ni/Au interdigitated electrodes based on GaN/i-GaN/c-Al2O3 heterostructure were fabricated. The current-voltage, transient photoresponse on- off and spectral characteristics of the formed photodetectors were studied. It was found that the devices have a maximum responsivity at a wavelength of 364 nm with full width at half maximum of 11 nm, thus the presented PDs are narrowband. 10.18721/JPM173.144 621.383.526 GaN ultraviolet photodetector narrowband photodetector metal-semiconductor- metal https://physmath.spbstu.ru/article/2024.75.44/

CNF RUS 224-228 Boltanskii Matvei m.boltanskiy@goqrate.com Maksimova Elizaveta e.maksimova@goqrate.com Fadeev Maxim mfadeev2022@gmail.com Shakhovoy Roman r.shakhovoy@goqrate.com Influence of optical feedback on an optical pulse shape of a semiconductor laser Gain-switched semiconductor lasers can produce pulses with naturally randomized phase, which makes them a convenient light source for quantum key distribution and random number generation. Nevertheless, semiconductor  lasers are vulnerable to external optical feedback, a phenomenon, characterized by injection of a certain part of laser radiation into the laser’s diode cavity. Although optical feedback may be used to decrease relaxation oscillations and chirp, it may have negative effect on laser pulses. Here, we study the influence of optical feedback on the pulse shape of a gain-switched laser. 10.18721/JPM.173.145 535.14 gain-switched laser optical feedback laser pulse interference https://physmath.spbstu.ru/article/2024.75.45/

CNF RUS 229-232 0000-0003-2282-3895 Savelyev Dmitry Dmitry dmitrey.savelyev@yandex.ru Optical needle formation by subwavelength optical elements using high-performance computer systems The optical vortex diffraction on subwavelength optical elements with a standard and GRIN substrate using the finite difference time domain method was simulated in this paper. The possibility of increasing the light needle (up to  7.86λ) for input radiation with azimuthal and radial polarization was shown using a GRIN substrate and a subwavelength element with zones alternating in height. 10.18721/JPM.173.146 535.42 optical vortices GRIN subwavelength ring gratings FDTD https://physmath.spbstu.ru/article/2024.75.46/

CNF RUS 233-237 Babichev Andrei scientific.ocean@gmail.com. 0009-0001-3683-5558 ITMO University Papylev Denis dspapylev@itmo.ru

St. Petersburg, Russian Federation

0000-0002-7025-3527 National Research University “Higher School of Economics” Komarov Sergey serega.komarow@mail.ru

St. Petersburg, Russian Federation

Kryzhanovskaya Natalia V. Natalia nkryzhanovskaya@hse.ru Ioffe Institute Blokhin Sergei blokh@mail.ioffe.ru

St. Petersburg, Russian Federation

Nevedomskiy Vladimir nevedom@mail.ioffe.ru 0000-0002-9448-2471 Connector Optics LLC Gladyshev Andrey andrey.gladyshev@connector-optics.com

St. Petersburg, Russian Federation

ITMO University Karachinsky Leonid lkarachinsky@itmo.ru

St. Petersburg, Russian Federation

ITMO University Novikov Innokenty innokenty.novikov@itmo.ru

St. Petersburg, Russian Federation

0000-0002-0789-4241 Alferov University Egorov Anton anton.egorov@connector-optics.com

St. Petersburg, Russian Federation

Study of planar microcavity structure with In0.63Ga0.37As quantum dots and non-absorbing Al0.2Ga0.8As/Al0.9Ga0.1As mirrors The planar microcavity structure based on non-absorbing Al0.2Ga0.8As/Al0.9Ga0.1As mirrors was fully fabricated by molecular-beam epitaxy. Usage of In0.63Ga0.37As quantum dots reveals room temperature emission near 1110 nm  with emission bandwidth of about 80 meV. The determined spectral mismatch between peak position of gain region and reflectivity spectrum dip was about 115 meV at 290 K. The shift of the reflectance dip position along the whole wafer surface was less than 15 meV. The determined by defect inspection root mean square surface roughness was less than 1.3 nm for studied 8 μm thick planar microcavity structure. 10.18721/JPM.173.147 535.37 molecular-beam epitaxy planar microcavity gallium arsenide InGaAs Stransky- Krastanow growth mode https://physmath.spbstu.ru/article/2024.75.47/

CNF RUS 238-242 0000-0002-5183-6807 Vasilevskaya Yulia Ksenofontova Polina Litvinova Kristina Savitskiy Andrey andr.savitskiy@gmail.com Memristive behavior of the system comprising Ag nanoparticles coated by HfOx layer Memristive systems promise energy-efficient computing and accelerated machine learning tasks by enabling simultaneous storage and processing of information within single device architecture. The research focuses on the analysis  of percolation memristive systems based on silver nanoparticles in a hafnium oxide dielectric matrix. Conductivity in the nanoparticle network is achieved through atomic filament connections between adjacent particles. The  systems exhibit hysteresis in I-V curves when a sawtooth electric voltage is applied. The hafnium oxide coating was used to provide sample stability and also to reduce the formation voltage due to the proposed additional mechanism  of valence change during subsequent filament formation. 10.18721/JPM.173.148 539.219.3 silver nanoparticles filament percolation neuromorphic computing https://physmath.spbstu.ru/article/2024.75.48/

CNF RUS 243-246 0009-0002-4770-8738 Pylaev Vadim 0000-0002-1945-1050 Bonch-Bruevich Saint Petersburg State University of Telecommunications Andreeva Elena

St. Petersburg, Russian Federation

Experimental study of the use of optical cables with different types of fibers in monitoring systems A comparative study of the sensitivity to point vibration of a single-fiber optical cable with standard single mode optical fiber (SSMF) and with bend loss insensitive optical fiber (BLIF) was carried out. The measurement was carried out  for a single vibration action – the fall of a kettlebell, and harmonic acoustic effects. During the experimental study, the advantage of the used optical cable with the bend loss insensitive optical fiber was revealed. 10.18721/JPM.173.149 681.7 fiber-optic reflectometers optical fiber Rayleigh scattering DAS fiber-optic acoustic distributed sensor https://physmath.spbstu.ru/article/2024.75.49/

CNF RUS 247-251 Neelova Angelina angelina.neelova@gmail.com 0009-0009-8987-4698 Lepekhina Tatiana 0009-0001-6814-1737 Zhurba Danila 0000-0002-7376-2263 Almiashev Vyacheslav 0000-0003-4098-2136 Aseev Vladimir assev@oi.ifmo.ru Parfenov Vadim vadim_parfenov@mail.ru A study of laser cleaning of paper with fat-containing contaminations This paper is devoted to investigation of laser cleaning of paper with fat-containing contaminations. In recent years, laser technologies have been widely used in the preservation of Cultural Heritage (CH). One of the main fields of  laser application in this area is the cleaning of CH objects from natural and anthropogenic contaminations. It is known that there exist two main approaches to the laser cleaning, e.g. dry cleaning and wet cleaning. We will present experimental results of wet laser cleaning with the Ytterbium fibre laser (wavelength of 1064 nm) of fat-containing contaminations from model samples and fragments of a real historical artefact such as XIXth century book. 10.18721/JPM.173.150 544.032.65 heritage science laser application laser cleaning https://physmath.spbstu.ru/article/2024.75.50/

CNF RUS 252-256 0000-0002-1945-1050 Bonch-Bruevich Saint Petersburg State University of Telecommunications Andreeva Elena

St. Petersburg, Russian Federation

0000-0001-8541-9916 Andreev Dmitry 0009-0001-3075-9558 Orlov Mikhail Isupov Alexander Investigation of the possibility of creating a broadband measuring source using the nonlinear properties of an optical fiber A computer simulation and experimental study of a broadband laser source for testing fiber-optic communication systems has been conducted. The study investigated the use of nonlinear optical effects in fiber to expand the  spectrum of a laser source. Two types of fiber were compared: standard single-mode fiber (SSMF) and dispersion shifted fiber (DSF), to determine the best parameters for the source. 10.18721/JPM.173.151 535.015 fiber-optic communication system Wavelength Division Multiplexing optical fiber nonlinear effects https://physmath.spbstu.ru/article/2024.75.51/

CNF RUS 257-260 0000-0001-8480-2016 Marasanov Dmitriy Litunovskiy Igor Pesniakov Vladislav v.pesnyackoff@yandex.ru Sgibnev Yevgeniy sgibnevem@gmail.com Nikonorov Nikolay nvnikonorov@corp.ifmo.ru Spectral and photocatalytic properties of Ag-AgCl nanostructures formed on surface of silicate glass by ion exchange In this work, the spectral and photocatalytic properties of 3 silicate glasses with different chlorine concentrations from 0.5 to 1 mol. % were studied. Since photocatalysts require the presence of nanostructures on the glass surface,  silver was introduced into silicate glass with chlorine by low-temperature Na+-Ag+ ion exchange. The synthesis of Ag-AgCl nanostructures occurred during heat treatment, after which a plasmonic absorption band in the visible range  of the spectrum was revealed in the absorption spectra. The degree of decomposition of the aqueous solution of methyl orange dye increased from 80 to 92% with increasing chlorine concentration in the photocatalyst with Ag-AgCl  nanostructures. Note that with increasing chlorine concentration, the concentration of nanostructures increases. 10.18721/JPM.173.152 535.342 ion exchange nanostructures nanocrystals silver absorption photocatalysis https://physmath.spbstu.ru/article/2024.75.52/

CNF RUS 261-265 0009-0007-7614-6734 Kartashova Anastasia 0000-0003-3281-8352 Saratov State University Serdobintsev Alexey alexas80@bk.ru

Saratov, Russian Federation

0000-0001-6780-9865 Volkovoynova Larisa Laser-stimulated tin-induced crystallization of silicon on flexible nonwoven substrates The work is devoted to the formation of polycrystalline silicon coatings on electrospinned nonwoven polyacrylonitrile mats using a metal layer absorbing laser radiation. The results of experimental studies confirming the presence of  crystallized silicon structures on nonwoven polymer substrates are presented. The efficiency of tin films with different thicknesses is compared when using them as upper laser-absorbing layers during laser-stimulated metal-induced crystallization of silicon. It was found out that during laser processing, the metal does not ablate completely and the remaining part of it is collected into particles, the size of which depends on the initial thickness of the metal film. It  has also been established that during the laser annealing process expansion or glass transition of fibers can occur. 10.18721/JPM.173.153 539.216.1, 539.231, 543.424.2 nanofibrous nonwoven material magnetron sputtering laser-stimulated silicon crystallization metal-induced silicon crystallization https://physmath.spbstu.ru/article/2024.75.53/

CNF RUS 266-270 0009-0003-9168-2421 Menshikov Evgenii evgenii.menshikov@metalab.ifmo.ru Lazarenko Petr aka.jum@gmail.com Terekhov Dmitry 0000-0002-9043-3197 Dostovalov Alexander dostovalov@iae.nsk.su 0000-0002-1382-3589 Kokhanovskiy Alexey a.kokhanovskiy@metalab.ifmo.ru Laser-induced switching of GST films using a spatial light modulator One of the promising materials enabling tuning of optical response in photonic devices is the class of chalcogenide optical phase-change materials (oPCMs), such as GeSbTe (GST). These materials exhibit nonvolatile amorphous  and crystalline phase states under normal conditions, while offering quick (ns-) phase switching and prominent optical contrast, which can be induced via laser irradiation. Direct laser modification of PCM films is usually realized  through a point-by-point approach, by sequentially scanning a focused laser beam over the film surface. Although this technique is straightforward and easy to implement, it significantly limits potential fabrication speeds. In this work,  we study a method of laser-induced switching of the phase state of GST films using a spatial light modulator. We demonstrate that this approach enables fast patterning of large areas of the material. 10.18721/JPM.173.154 53.043 phase-change materials GeSbTe laser imprinting spatial light modulator https://physmath.spbstu.ru/article/2024.75.54/

CNF RUS 271-277 Nikitin Konstantin halkwww@mail.ru National Research University of Electronic Technology Barsukov Leonty leonty.barsukov@gmail.com

Moscow, Russian Federation

Romashkin Alexey romaleval@gmail.com 0000-0002-2976-9775 Trifonov Alexey 0000-0002-8578-3977 Mozhchil Rais 0009-0007-7675-3876 Protasova Svetlana sveta@issp.ac.ru Low-temperature treatment of Al/Ti nanolayers to form solid solution in order to improve the ohmic contacts process formation Heat treatment of the Al, Al/Ti and Au/Ni/Al/Ti nanolayers at 450 °C was studied by measuring transparency, resistivity and also by SIMS (secondary ion mass spectrometry) and XPS (X-ray photoelectron spectroscopy). Heat  treatment has led to the increase in transparency and in resistivity of Al/Ti films. On the contrary, the same treatment for the pure Al layer decreases resistivity but transparency increases due to the decrease in the unoxidized Al  thickness. The upper Au/Ni layer has led to greater changes in resistivity and transparency but presumably due to a higher oxidation degree, that confirmed by XPS. Observed changes of the Al/Ti layer structure are assumed to be  explained not only by oxidation, but also by the partial formation of a Ti-Al solid solution, confirmed by SIMS (Ti and Al redistribution in the layer). The suppression of oxidation, Ti-Al formation temperature reduction and, as a result, possibility to improve GaN HEMT ohmic contacts with such layers were studied. 10.18721/JPM.173.155 [621.785.3:539.216.2:(669.295+669.71)]::621.3 thin film rapid thermal annealing ohmic contact TiAl compounds transparency Raman spectroscopy SIMS XPS https://physmath.spbstu.ru/article/2024.75.55/

CNF RUS 278-282 0000-0003-3849-108X Fetisenkova Ksenia fetisenkova.ka@phystech.edu Melnikov Alexander Alexen96@gmail.com Miakonkikh Andrey miakonkikh@ftian.ru Rogozhin Alexander rogozhin@ftian.ru Tatarintsev Andrey tatarintsev@ftian.ru E-beam resist AR-N 7520 in the formation of the photonic structures The study of plasma resistance of the AR-N 7520 was carried out. The selectivity of the reactive ion etching (RIE) of silicon through the mask of negative electron resist AR-N 7520 also was investigated. The dependence for  selectivity was obtained at different fractions of SF6 in the feeding gas and at the different values of bias voltage. A high etching selectivity of 8.0 ± 1.8 was obtained for the etching process. The dependence of the resist line height  on the exposure dose is presented. The optimal value for the line exposure dose was found to be 8200 pC/cm. 10.18721/JPM.173.156 537.533.9 electron-beam lithography etching kinetic novolak reactive-ion etching waveguide https://physmath.spbstu.ru/article/2024.75.56/

CNF RUS 283-287 Eurov Daniil edan@mail.ru Stovpiaga Ekaterina kattrof@gvg.ioffe.ru 0000-0002-1571-209X ITMO University Kirilenko Demid demid.kirilenko@mail.ioffe.ru

St. Petersburg, Russian Federation

Ioffe Institute Kurdyukov Dmitry kurd@gvg.ioffe.ru

St. Petersburg, Russian Federation

Formation of mesoporous silica coating on cores with different surface properties An approach has been developed for the wet synthesis of mesoporous silica shell on the surface of various spherical composite particles with different zeta potential. It is demonstrated that the surface charge of the core particles  influences the porous structure of the obtained shell. The proposed method allows obtaining a uniform layer of the same thickness on the surface of each core particle preventing their coalescence. 10.18721/JPM.173.157 54.057 spherical particles core-shell nanostructures silica zeta potential mesopores https://physmath.spbstu.ru/article/2024.75.57/

CNF RUS 288-292 Khramov Artem Federal State Budgetary Institution of Science K.A. Valiev Institute of Physics and Technology of the RAS Yaroslavl Branch Savinsky Nikolay savinski1@yandex.ru

Yaroslavl, Russian Federation

Federal State Budgetary Institution of Science K.A. Valiev Institute of Physics and Technology of the RAS Yaroslavl Branch Grushevsky Egor yaregor@mail.ru

Yaroslavl, Russian Federation

Evolution of crystalline phases of P(VDF-TeFE) films filled with nanographite in various aprotic solvents The work under discussion describes the preparation and study copoly(vinylidene fluoride–tetrafluoroethylene) (P(VDF–TFE)) films filled with chemically exfoliated nanographite and crystallized by drying from various solvents. The  content of α, β and γ phases of PVDF was estimated via Fourier transform infrared spectroscopy (FTIR) and supported by Raman spectroscopy and X-ray diffractometry. Experimental study revealed that films made from a solution of  dimethyl sulfoxide (DMSO) have a higher content of the polar β-phase and films filled with nanographite showed increased degree of of β-phase content. 10.18721/JPM.173.158 537.226 poly(vinylidenefluoride–tetrafluoroethylene P(VDF-TeFE) dimethyl sulfoxide (DMSO) dimethylformamide (DMF) beta phase FTIR XRD nanographite https://physmath.spbstu.ru/article/2024.75.58/

CNF RUS 293-296 Ignatieva Irina iignateva@sfedu.ru 0000-0002-3779-8242 Starnikova Alexandra starnikova@sfedu.ru 0000-0003-3725-6053 Petrov Viktor vvpetrov@sfedu.ru Bayan Ekaterina ekbayan@sfedu.ru Optical properties of the CuO-ZnO thin films In this work, we investigate the optical properties of CuO-ZnO thin films formed on quartz substrate. CuO-ZnO nanocomposite films were obtained by solid-phase pyrolysis with different atomic Cu:Zn ratios (1:99, 3:97, 5:95, 10:90)  and annealed at a temperature of 600 °C. The crystal structure of the films was studied, and their optical transmission spectra were analyzed. It was found that transmittance is more than 84% for all materials in the range from 400 to 1000 nm. 10.18721/JPM.173.159 546.05; 538.975 zinc oxide copper oxide composite thin films optical properties https://physmath.spbstu.ru/article/2024.75.59/

CNF RUS 297-301 0009-0005-6189-4567 Ushakova Olga 0000-0002-8286-0711 Lugovitskaya Tatyana Shipovskaya Anna Shipovskayaab@yandex.ru Supramolecular ordering of thin glycerohydrogel plates of chitosan L- and D-aspartate The supramolecular ordering of thin glycerohydrogel plates of chitosan L- and D-aspartate was studied using small-angle X-ray scattering (SAXS) and transmission electron microscopy (TEM). At the nanolevel of supramolecular  organization of the objects under study, two forms of scattering inhomogeneities were revealed, namely: nanospheres and nanorods. In CS·L-AsрA-based plates, larger scattering nanoaggregates and their less symmetrical ordering  in the solid-phase state of the polymeric substance were found. 10.18721/JPM.173.160 547.458:[539.264+539.25] chitosan L- and D-aspartic acid glycerohydrogel plates small-angle X-ray scattering microscopy https://physmath.spbstu.ru/article/2024.75.60/

CNF RUS 302-305 Pesniakov Vladislav v.pesnyackoff@yandex.ru 0000-0001-8480-2016 Marasanov Dmitriy Sgibnev Yevgeniy sgibnevem@gmail.com Nikonorov Nikolay nvnikonorov@corp.ifmo.ru Photocatalytic properties of Ag-AgBr nanostructures formed by ion-exchange in photo-thermo-refractive glass for water-dye degradation In this paper Ag-AgBr nanostructures photocatalytic properties were studied. Hybrid nanoparticles were grown in photo-thermo-refractive glass during the ion exchange in AgNO3 solution and subsequent heat treatment. XRD study  demonstrated the growth of Ag nanoparticles with increase of bromine concentration. Water-dye degradation rate shows that with increase of bromine concentration photocatalytic properties of glass are also increases. 10.18721/JPM.173.161 541.145 photocatalysis PTR glass silver nanoparticles semiconductor nanoparticles https://physmath.spbstu.ru/article/2024.75.61/

CNF RUS 306-309 0000-0002-4110-1647 Shugabaev Talgat talgashugabaev@mail.ru Gridchin Vladislav gridchinvo@gmail.com 0000-0001-7143-6686 Kusnetsov Alexey alkuznetsov1998@gmail.com Kulagina Anastasia a.s.panfutova@gmail.com St. Petersburg State University Khrebtov Artem khrebtovart@mail.ru

St. Petersburg, Russian Federation

Lendyashova Vera erilerican@gmail.com Reznik Rodion moment92@mail.ru Cirlin George george.cirlin@mail.ru Influence of the wet-chemical treatment on the optical and structural properties of core-shell InGaN nanowires We study the influence of the shell in InGaN nanowires with spontaneously formed core-shell structure on their optical and morphological properties. It is shown that removing the shell from the initial nanowires induces the  photoluminescence enhancement and changes their spectrum emission. Our research shows that etching the shell of these nanowires nanocrystals leads to their deviation from the vertical position. 10.18721/JPM.173.162 535.3 core-shell InGaN nanowires etching of nanowires photoluminescence enhancement molecular beam epitaxy https://physmath.spbstu.ru/article/2024.75.62/

CNF RUS 310-314 0009-0009-6573-0841 Ratova Anastasia ITMO University Babkina Anastasiia babkina.anastasya@bk.ru

St. Petersburg, Russian Federation

0000-0002-9146-8519 Kharisova Rufina Zyryanova Ksenia ms.z.k.s@mail.ru Luminescent properties of glasses activated by CsPbBr3 perovskite nanocrystals and europium ions A series of borogermanate glasses with CsPbBr3 perovskite nanocrystals and Eu3+ ions is synthesized. At low concentrations of Eu2O3 in glass, Eu3+ ions play the role of crystallization centers for the nucleation of perovskite nanocrystals. At high concentrations of Eu2O3 in glass, CsPbBr3 nanocrystals nucleate only during additional heat treatment. The lifetime of Eu3+ luminescence increases from 1.58 to 1.69 msec along with an increase in the Eu2O3  concentration. Along this, a slight distortion of the Eu3+ environment occurs in the glass matrix, resulting in a slight redistribution of the characteristic luminescence bands. 10.18721/JPM.173.163 535.372 perovskite nanocrystals borogermanate glasses trivalent europium https://physmath.spbstu.ru/article/2024.75.63/

CNF RUS 315-319 0009-0006-2524-7618 Boitsova Natalia 0000-0003-3859-6981 Abelit Anna 0000-0002-3756-0701 Verlov Nikolai 0000-0002-5470-9301 Stupin Daniil Using Monte-Carlo based randomisation for stabilisation of data fitting in bioimpendance spectroscopy: Proof-of-concept Nowadays, a lot of bioimpedance devices are proposed and signal processing for them is still under intensive development. In this study, we improved the complex non-linear least squares (CNLS) protocol for non-stationary  bioimpedance data analysis. To be specific, we tested different Monte-Carlo applications for choosing starting point for CNLS approximation – an essential step for every non-linear problem. As a result, we have proved that symbiosis  approach with usage of the CNLS-solution of the previous spectra as starting point and global Monte-Carlo searching of the starting point is the promising powerful combination for such a task. 10.18721/JPM.173.164 621.317 bioimpedance CNLS Monte-Carlo https://physmath.spbstu.ru/article/2024.75.64/

CNF RUS 320-324 0000-0002-5470-9301 Stupin Daniil 0009-0006-2524-7618 Boitsova Natalia 0009-0009-3972-777X Dubina Phillip filipp.dubina@gmail.com 0000-0002-3756-0701 Verlov Nikolai 0000-0003-3859-6981 Abelit Anna Autostainer feature for multielectrode arrays: proof-of-concept Today, bioelectronics technologies are opening new horizons and paving the way for future development using a wide range of materials. For example, numerous purely electronic materials, such as silicon, textolite and various  polymer masks, are very promising for the purposes of cellular bioelectronics in vitro, but their optical properties limit their use, since modern microscopic control is still the most reliable tool for live cell diagnostics. This problem can  be solved with the help of special dyes, however the staining procedure requires reagents and time, which on an industrial scale will lead to costs and a slowdown in the production process. Here we propose a solution to this issue  based on the fabrication of cell-based bioelectronic devices that automatically stain cells without any additional sample manipulation. 10.18721/JPM.173.165 621.317 MEA autostainer Hoechst silicon PETG https://physmath.spbstu.ru/article/2024.75.65/

CNF RUS 325-329 Suchkova Victoria molodykh1999@gmail.com I.M. Sechenov First Moscow State Medical University Ryabkin Dmitrii ryabkin@bms.zone

Moscow, Russian Federation

Varlamova Polina National Research University of Electronic Technology Gerasimenko Alexander gerasimenko@bms.zone

Moscow, Russian Federation

Solder based on nanoparticles with metallic properties for laser reconstruction of blood vessels Laser blood vessel reconstruction is a modern, non-invasive method of blood vessel closure. Until now, most previous work has used protein and dye-based solders (laser absorbers) to form welds. However, the addition of  nanoparticles to the solder, which have outstanding bactericidal properties and the ability to accelerate wound epithelialisation, has the potential to improve the efficiency of optical wound healing. The aim of the study was to experimentally investigate the physicochemical properties of dispersed solders including antibacterial nanoparticles of metals Ni, Al, Fe3O4 and carbon nanotubes with metallic properties, biopolymer – albumin, and dye localizing  laser radiation in the area of wound dissection – indocyanine green, the formation of a biological tissue compound and the study of their mechanical properties. The selected nanoparticles have a high absorption coefficient of laser  radiation, which provides high efficiency of laser energy utilization and allows recovery with minimal losses. The effectiveness of solders with different metal nanoparticles was experimentally tested in cattle vessels. Tissue  reconstruction was performed by diode laser with a wavelength of 810 nm. The suture was formed within 1 minute. The laser exposure temperature was 55 °C for each particular specimen. The results showed that the highest tensile  strength was in the specimen with carbon nanotubes. The achieved strength with carbon nanotubes was 950 kPa. 10.18721/JPM.173.166 004.852 vessel reconstruction nanoparticles laser soldering https://physmath.spbstu.ru/article/2024.75.66/

CNF RUS 330-334 Antipenko Vladimir v.antipenko7@yandex.ru Pecherskaya Ekaterina pea1@list.ru Yakushov Dmitriy hammer.fate@yandex.ru 0000-0002-3240-7222 Penza State University Artamonov Dmitriy dmitrartamon@yandex.ru

Penza, Russian Federation

0000-0002-2697-3260 Penza State University Karpanin Oleg

Penza, Russian Federation

0000-0001-5075-2727 Penza State University Shepeleva Juliya

Penza, Russian Federation

Reducing the error in measuring bioimpedance when studying body composition Automated bioimpedance measurement systems are part of modern medicine because they provide the ability to determine body composition and provide performance parameters. Bioimpedance analysis has the advantage of being  able to test non-invasively, and accuracy and availability continue to improve every year. Currently, when assessing bioimpedance parameters, special attention is paid to the methods and accuracy of measurements. This  article discusses key aspects of bioimpedance determination related to measurement errors. Various approaches to reducing errors in bioimpedance measurements are also presented. 10.18721/JPM.173.167 621.37 impedance measurement Сole model error object https://physmath.spbstu.ru/article/2024.75.67/

CNF RUS 335-339 0009-0004-6601-8884 Nefediev Nikolay Nikolay-Nefedev@yandex.ru 0000-0002-4404-5222 Staroverov Nikolay Davydov Roman davydovroman@outlook.com Improving compliance of brain MRI studies with the atlas using a modified TransMorph neural network The work carried out a study on modifying the architecture of the TransMorph neural network by integrating an input data preprocessing unit. The goal was to achieve better similarity scores between studies in the dataset and the  reference atlas. The data was assessed based on the structure similarity metric. The results suggest that the use of a Sobel filter can lead to improvement. 10.18721/JPM.173.168 004.032.26 DIR TransMorph brain segmentation MRI neural network AI in medicine https://physmath.spbstu.ru/article/2024.75.68/

CNF RUS 340-344 Federal State Budgetary Institution of Science K.A. Valiev Institute of Physics and Technology of the RAS Yaroslavl Branch Shlepakov Pavel p.shlepakov@bk.ru

Yaroslavl, Russian Federation

Uvarov Ilia i.v.uvarov@bk.ru Svetovoy Vitaliy svetovoy@yandex.ru A fast and strong microactuator powered by explosion of a hydrogen-oxygen mixture An electrochemical actuator is demonstrated that uses the periodic explosions of hydrogen and oxygen gases in a microchamber with a volume of 3.1 nl. The gases are generated in the form of nanobubbles during alternating  polarity electrolysis. The device operates at a frequency of up to 10 Hz. The stroke of the membrane can reach 100 μm, which is an order of magnitude larger than the deflection in the non-explosive mode. No significant wear of the  device is observed after 40 000 explosions in the chamber. The output force is measured by loading the membrane with different objects. The actuator develops a force at least 0.5 N, significantly outperforming other actuators in  terms of force density. 10.18721/JPM.173.169 62-83 electrochemical actuator membrane alternating polarity electrolysis nanobubbles explosion force https://physmath.spbstu.ru/article/2024.75.69/

CNF RUS 345-348 Razakova Anita aa_razakova@student.mpgu.edu Prikhodko Anatoliy anatprikh1995@yandex.ru Lvov Andrey andrei.lvov1707@yandex.ru Shurakov Alexander alexander@rplab.ru Goltsman Grigory goltsman@rplab.ru Subterahertz circularly polarized 1k-pixel reflective surface for 6G applications Wireless communication is a hot topic of research and development at this moment. The need of increasing data transfer rates and connection stability within vast digitalization of people interactions sets new tasks for scientific  community. One of them is the utilization of higher operating frequencies in range of 140–150 GHz. This is an obvious way to obtain bigger channel capacity. However, for line-of-sight wireless channels, it may potentially lead to severe propagation losses, including absorption in water-containing atmospheric environments and scattering off static or dynamic objects. In this work, we report on the development of a technologically robust reflective surface that  can be used in the sixth-generation reflection-aided data links. The proposed reflective surface has 36×36 spiral metallic elements implemented on top of a thin back-metalized quartz plate. The fabricated prototype was designed for  50° deflections from specular propagation paths at angles of incidence within ±75° and successfully used for a non-distorting reflection of a 6º wide Gaussian beam at 145 GHz. It supports both linear and circular polarizations and exhibits cross-polarization level of approximately −25 dB. 10.18721/JPM.173.170 621.396.42 subterahertz reflectarray antenna wireless channel 6G communication https://physmath.spbstu.ru/article/2024.75.70/

CNF RUS 349-353 0009-0009-6785-4389 Ershova Margarita mi_ershova@student.mpgu.edu Prikhodko Anatoliy anatprikh1995@yandex.ru Shurakov Alexander alexander@rplab.ru Goltsman Grigory goltsman@rplab.ru A mm-wave dielectric antenna with symmetric beam compatible with PCB machinery The current decade is associated with the start of active deployment and use of fifth generation networks, while the ongoing developments in the sixth generation communication technologies should be finalized in the upcoming  decade. It is forecasted that sufficiently directive wireless transceivers will become integral parts of the next generation wireless communication systems. In this study, we report on the development of a low-cost millimeter wave dielectric antenna with nearly symmetric beam. The antenna makes use of a dual-stage dielectric multimode interference power divider terminated by 16 dielectric tapers with flare angles of 6–12°. It is designed for operation at  frequencies of 50–77 GHz. The design is developed for fabrication by the means of printed circuit board prototyping machinery from high-permittivity laminates and, therefore, is compatible with the Si platform for solid-state  electronics and integrated photonics. The fabricated antenna samples exhibit half-power beamwidths of 27° with corresponding side lobe levels of approximately –10 dB, as measured at 52 GHz. 10.18721/JPM.173.171 621.396.42 millimeter wave dielectric rod antenna antenna array high-permittivity laminate direct machining https://physmath.spbstu.ru/article/2024.75.71/

CNF RUS 354-357 ITMO University Burmistrov Oleg oleg.burmistrov@metalab.ifmo.ru

St. Petersburg, Russian Federation

ITMO University Olekhno Nikita nikita.olekhno@metalab.ifmo.ru

St. Petersburg, Russian Federation

Wireless power transfer in magnetic resonance imaging with a detuned birdcage coil In this work, we develop an application of a transmit birdcage coil for wireless power transfer during the receive phase within a magnetic resonance imaging (MRI) scanner. The study includes numerical simulations and an  experimental verification of a numerical model with a clinical birdcage coil. We simulate numerically magnetic fields inside the magnetic resonance imaging scanner with a phantom, the specific absorption rate distributions with a  human voxel model, and the resulting voltage on receiving system coils. Therefore, we characterize possible distortions in MR images, demonstrate safety of the setup for a patient, and evaluate the RF-RF efficiency numerically,  respectively. Finally, we outline potential devices placed in MRI bore which can provide a wireless power supply with the detuned birdcage coil and receive system. 10.18721/JPM.173.172 537.86 MRI magnetic resonance imaging birdcage coil WPT wireless power transfer resonators https://physmath.spbstu.ru/article/2024.75.72/

CNF RUS 358-362 Valov Anton tony.valov2015@yandex.ru Isupova Ekaterina isupova.e24@mail.ru Zaletov Dmitriy Development of an excitation signal generation system for a rubidium frequency standard In the digital age, information transmission systems, telecommunications and satellite navigation systems, as well as metrology services play an important role. However, the development of these technologies leads to the need to  constantly improve the frequency standards used for signal synchronization. To improve the stability of the signal produced by the frequency standard, a new system has been proposed for generating a microwave signal with a  frequency that matches the frequency of the atomic transition of rubidium-87 atoms. 10.18721/JPM.173.173 004.032.32 frequency standard atomic clock phase-locked loop frequency synthesizer stabilization https://physmath.spbstu.ru/article/2024.75.73/

CNF RUS 363-366 0009-0005-6258-9353 Rozhkova Polina pv_rozhkova2@student.mpgu.edu Prikhodko Anatoliy anatprikh1995@yandex.ru Shurakov Alexander alexander@rplab.ru Goltsman Grigory goltsman@rplab.ru Polyethylene-on-quartz platform for subterahertz reconfigurable reflective surfaces Subterahertz frequency band is preallocated for the deployment of sixth generation wireless networks. Mastering of this band is challenging and requires development of appropriate hardware and software. The properties of  components used should be authentically known for the purpose of accurate designing and prototyping. This research focuses on the radiophysical properties of a polyethylene-on-quartz sandwich as a potential dielectric platform  for the implementation of reconfigurable reflective surfaces. The sandwich is exposed to spectral studies, statistical analysis of feasible fabrication tolerances and compatibility with cleanroom metal deposition and patterning  processes. Its technological robustness is assessed upon prototyping of a 16-element planar reflectarray designed for operation in specular and non- specular reflection regimes at 155 GHz and 120 GHz, respectively. Using the  measured value of quartz permittivity of a 3.55 and the loss tangent of a 0.001, we calculate the reflectarray reflection losses of approximately 1.5 dB. The calculations agree well with the results of its radiation pattern measurements  conducted at 155 GHz. This hints that the developed passive platform is suitable for integration with A3B5 active layers with nonlinear elements ensuring fast beam steering in the subterahertz band. 10.18721/JPM.173.174 621.396.42 subterahertz polyethylene-on-quartz permittivity reconfigurable reflective surface reflection loss 6G network https://physmath.spbstu.ru/article/2024.75.74/

CNF RUS 367-371 0000-0002-1098-0300 Bagrov Alexander alexander.bagrov00@mail.ru 0000-0001-8682-4956 Bashkirov Evgeniy bash@ssau.ru Thermal entanglement in the three-qubit Tavis-Cummings model with many-photon transitions In this paper, we consider the model consisting of an isolated qubit and two qubits trapped in a lossless cavity and interacting with cavity thermal field via many-photon transitions. We obtain the exact solution of the model under  consideration. On its basis we calculate the negativity as a measure of pair qubits entanglement. It is shown that, for many-photons processes entanglement is stronger than for that in the linear one-photon processes and can suppress the sudden death of qubit-qubit entanglement. The pairwise entanglement transfer between qubits pairs are also observed. 10.18721/JPM.173.175 530.145.83. qubits thermal field entanglement many-photon transitions sudden death of entanglement cavity https://physmath.spbstu.ru/article/2024.75.75/