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Optical properties of disk microresonators based on wide-bandgap III-N materials
St. Petersburg Polytechnical University Journal: Physics and Mathematics. 2025. Vol. 18. No. 3.1. P. 209–213.
S.D. Komarov, Vainilovich A. G., G.A. Feigin, Sakharov A. V., Nikolaev A. E., K.A. Ivanov, E.I. Moiseev, N.V. Kryzhanovskaya, A.E. Zhukov
Fabrication, optical study, and mode modeling of III-N microdisk resonators with InGaN/GaN quantum wells on Al2O3 are presented. It is shown that the created epitaxial structures have high optical quality, and the microresonators support high-Q whispering gallery modes.
Zirnik G., Ostovari Moghaddam A., Zhukov S. et al., Journal of Materials Science: Materials in Electronics 2026 Vol. 37 Article 738
In regards to the advances in InGaZnO for flexible transistors applications, herein for the first time we measure the broadband radio-frequency range (10 Hz to 1 MHz) dielectric permittivity ε′ and electrical conductivity σ of InGaZnO4 nanoparticle layers at different temperatures ranging from 10 to 300 K. The InGaZnO4 nanoparticles prepared by metal–nitrate–glycol gel decomposition method exhibited ...
Added: June 6, 2026
Flamarion M. V., Pelinovsky E., Nonlinear Dynamics 2026 Vol. 114 Article 784
In this article, we investigate wave packet and solitary wave dynamics in the Whitham–Ostrovsky (WO) equation. By means of a multiple-scales expansion, we formally derive a nonlinear Schrödinger (NLS) equation governing the envelope evolution.The corresponding modulational stability diagram is then obtained using the Lighthill criterion. We show that sufficiently large values of the low-frequency dispersive term render ...
Added: June 5, 2026
Hazarika A. P., Das A., Das S. K. et al., Physica B: Condensed Matter 2026 Vol. 738 Article 418803
Lemon grass (Cymbopogon citratus, LG-SiO2), horsetail (Equisetum debile, SG-SiO2), and cassava leaves (Manihot esculenta, CL-SiO2) were used to green-synthesize silica (SiO2) nanoparticles (NPs). While LG-SiO2 and SG-SiO2 had strong (101) peaks and a large 22° amorphous peak, XRD of CL-SiO2 verified crystallinity. LG-SiO2 (agglomerated porous), SG-SiO2 (rectangular-cube agglomerates), and CL-SiO2 (flake agglomerates) had different morphologies. The TEM image of LG-SiO2 revealed agglomerated ...
Added: June 4, 2026
Kornbleuth M., Opher M., Drake J. F. et al., Astrophysical Journal 2026 Vol. 1004 No. 1 Article 1
The shape of the heliosphere, regarded as comet-like since the 1960s, has recently been the subject of intense debate in the last decade. There is disagreement as to whether the heliospheric tail extends to ∼10,000 au in a comet-like shape or if it is short (∼400 au) with a split. Energetic neutral atom (ENA) maps from ...
Added: June 3, 2026
Kartsev A., Nishant T., Saswata G. et al., Journal of Materials Chemistry C 2026 Article -
Overheating remains a critical limitation in high-performance electronic and computing systems,
necessitating the development of efficient thermal management fluids. In this work, a magnetically
responsive hybrid ferrofluid was developed by incorporating two-dimensional hexagonal boron nitride
(2D-hBN) nanosheets into a Mn–Zn–ferrite-based ferrofluid. The hybrid system retains magnetic
responsiveness while leveraging the high in-plane thermal conductivity and chemical stability of 2D-hBN
nanosheets. ...
Added: June 2, 2026
Fortuna A. S., A.I. Kartsev, Gorshenkov M. V. et al., Journal of Alloys and Compounds 2026 Vol. 1070 Article 188711
The τ-phase in Mn-Al-Ga alloys is a promising candidate for rare-earth-free permanent magnets. This study re-veals that the τ(γ₂)-phase in rapidly quenched Mn55Al36Ga9 ribbons contains a high density of dislocations, which
form antiphase boundaries (APBs). Using transmission electron microscopy and density functional theory, we
demonstrate that Mn atoms at these APBs couple antiferromagnetically. This antiferromagnetic interaction is
identified ...
Added: June 2, 2026
Dikhtievskaya K., Argunov E., Kartsev A. et al., The Journal of Physical Chemistry Letters 2026 Vol. 17 No. 17 P. 4999–5004
In this study we revealed the effect of scandium doping on the electronic and superconducting properties of the MgB2 compound. Calculations demonstrate that Sc substitutes for Mg atoms, acting as an electron donor. Mg substitution diminishes the density of states in the σ-band and attenuates the electron–phonon coupling, thereby elucidating the reduction in critical temperature. Simultaneously, ...
Added: June 2, 2026
Duran E. ., Pulgar A., Izquierdo R. et al., Physica Status Solidi (A) Applications and Materials 2026 Vol. 223 No. 7 Article e202500942
Ceramic superconductors exhibit remarkable properties, including zero electrical resistance and potent magnetic behavior, operating at temperatures as high as the boiling points of liquid nitrogen (77 K) and liquid hydrogen (20 K). These characteristics position them as key enablers for sustainable technologies spanning electric propulsion, lossless energy transmission, advanced medical imaging, and quantum computation. This review presents ...
Added: June 1, 2026
Borisov V., Danilov V., Электросвязь 2025 № 12 С. 73–84
Представлены результаты математического моделирования процесса полевой эмиссии из катода малых размеров – одного из основных физических процессов, обеспечивающих работы многих электронных устройств, в частности FED-дисплеев (устройства, работающие на принципе полевой эмиссии), кантилеверов и т.д. Дается краткий обзор текущих результатов в области исследования, обосновывается актуальность задачи, приводятся примеры наиболее вероятного использования результатов решения задачи. Обсуждаются физические ...
Added: May 29, 2026
Jiang Q., Fang J., Chen J. et al., Science China Information Sciences 2026 Vol. 69 No. 6 Article 162402
Resonators based on nanoelectromechanical systems (NEMS) using two-dimensional (2D) materials with high-quality factors and excellent electrical control are critical for tunable coherent phonon dynamics, resonant sensors and wireless communications. However, their performance is fundamentally limited by the lack of a unified framework governing energy dissipation mechanisms and their electrical tunability. Here, we synergistically modulate both ...
Added: May 28, 2026
Elesin L., Shilov A., Jana S. et al., Advanced Functional Materials 2026 P. 1–10
Thermoelectric materials, long explored for energy harvesting and thermal sensing, convert heat directly into electrical signals. Extending their application to the terahertz (THz) frequency range opens opportunities for low-noise, bias-free THz detection, yet conventional thermoelectrics lack the sensitivity required for practical devices. Thermoelectric coefficients can be strongly enhanced near van Hove singularities (VHS), though these ...
Added: May 28, 2026
Degtyarev A., Bakhurin S., Yudin N., DSPA 2026 P. 1–6
This paper investigates one possible solution to the problem of self-interference cancellation (SIC) arising in the design of in-band full-duplex (IBFD) communication systems. Self-interference cancellation is performed in the digital domain using multilayer nonlinear models adapted via gradient-based optimization. The presence of local minima and saddle points during the adaptation of multilayer models limits the ...
Added: May 26, 2026
Qian X., Deng Y., Lev N. Shchur et al., Physica A: Statistical Mechanics and its Applications 2026 Vol. 696 Article 131679
We perform a Monte Carlo analysis of the Ising model on many three-dimensional lattices. By means of finite-size scaling we obtain the critical points and determine the scaling dimensions. As expected, the critical exponents agree with the three-dimensional Ising universality class for all models. The irrelevant field, as revealed by the correction-to-scaling amplitudes, appears to ...
Added: May 24, 2026
Babichev A., Makhov I., Kryzhanovskaya N. et al., IEEE Journal on Selected Topics in Quantum Electronics 2026 Vol. 32 No. 6 Article 1700208
Micropillar cavity lasers demonstrate operation up to 255 K. At this temperature, the lasing threshold and Q-factor, extracted at lasing threshold for a 4 μm diameter pillar are about 2 mW and 16800. For pillar lasers, the concept of which is based on an optical aperture, continuous-wave lasing is realized at room temperature (300 K). ...
Added: March 23, 2026
Kartsev A., Сафронов А. А., Махов М. И., Журнал радиоэлектроники 2024 № 3
In this paper, we find an analytical expression for the energy spectrum of a particle in a one-dimensional potential well with infinitely high walls. One of the walls with the coordinate x = 0 is motionless, the other wall, which has the coordinate x = a at the initial moment of time, moves at a constant speed. The results obtained can ...
Added: March 16, 2026
Бабичев А. В., Makhov I., Kryzhanovskaya N. et al., Письма в Журнал технической физики 2025 № 21 С. 58–62
Продемонстрирована генерация в микролазерах на основе вертикального микрорезонатора при температуре 244 K. Пороговая поглощенная оптическая мощность, длина волны генерации и добротность микролазера с диаметром 4 µm составили ∼ 2.8 mW, 989 nm и 12 000 соответственно. Минимальная пороговая поглощенная оптическая мощность (250 µW) соответствует температуре 168 K. ...
Added: March 13, 2026
Babichev A., Blokhin A., Zadiranov Y. et al., Applied Physics Letters 2026 Vol. 128 No. 5 Article 051105
High-quality micropillar cavities were grown using molecular-beam epitaxy. Stable continuous-wave lasing at room temperature was demonstrated for microlasers with semiconductor and hybrid output mirrors. At 300 K, single-mode lasing was demonstrated for micropillars with a diameter of 5 um at a wavelength of 960 nm, with a minimum lasing threshold of 1.2 mW and the ...
Added: March 13, 2026
D.A. Masyutin, A.A. Rudnev, E.I. Moiseev et al., St. Petersburg Polytechnical University Journal: Physics and Mathematics 2025 Vol. 18 No. 3.1 P. 125–128
In this work, we present results on high-temperature operation microdisk lasers with an active region based on InGaN/GaN quantum wells. The diameter of the microdisks was 5 μm. The photoluminescence spectra measured in the temperature range from 25 °С to 100 °С. The temperature stability lasing is demonstrated. ...
Added: December 11, 2025
Zhukov A., Moiseev E., Makhov I. et al., Письма в Журнал технической физики 2025 Т. 51 № 20 С. 32–35
The dynamic characteristics of an InGaAs/GaAs quantum dot microring laser were investigated using small-signal high-frequency current modulation at 55 °C. The maximum modulation bandwidth was 3.7 GHz, and the energy consumption during optical transmission was estimated to be 4.2–6.4 pJ/bit. The temperature dependencies of the parameters affecting the speed of operation (K-factor, threshold current, current ...
Added: October 29, 2025
Пеетерс Ф. М., Mahdavifar M., Khoeini F., Journal of Applied Physics 2024 Vol. 136 Article 184301
The impact of vacancies on spin-resolved electronic properties of quantum dots (QDs) in phosphorene-based junctions is investigated numerically. Regardless of the crystal orientation, a phosphorene nanoribbon containing a monovacancy is found to exhibit a topological quasi-flatband that emerges within the bandgap. The electronic properties of QDs, including spatial confinement and energy level distribution, can be ...
Added: September 15, 2025
Konstantin A. Ivanov, Alexey E. Zhukov, Eduard I. Moiseev et al., Journal of Applied Physics 2025 Vol. 138 No. 10 Article 103104
Microlasers supporting whispering gallery modes attract great interest because of their potential use in photonic integrated circuits: they have size just an order of magnitude larger than their emission wavelength and exhibit good thermal and dynamic properties. It is usually assumed that in disk microlasers a whispering gallery mode of the highest azimuthal order and ...
Added: September 11, 2025
Fominykh N., Fedosov I. S., Kryzhanovskaya N. et al., Письма в Журнал технической физики 2025 Т. 51 № 19 С. 11–14
The directed emission output of microdisk lasers through a coupled optical waveguide fabricated from the same heterostructure has been investigated. Disks with diameters of 30 and 40 µm containing an active region based on InGaAs/GaAs quantum dots were studied. To reduce absorption losses in the waveguide, a forward bias was applied to it. At a ...
Added: August 27, 2025
Moiseev E., Komarov S., Ivanov K. et al., Письма в Журнал технической физики 2025 Т. 51 № 11 С. 41–45
Созданы микродисковые лазеры с использованием полупроводниковой структуры InGaN/GaN на подложке Si. Продемонстрирована лазерная генерация при комнатной температуре в микролазерах диаметром 5−8 μm, работающих при оптической накачке в импульсном режиме на модах шепчущей галереи. Продемонстрирован сдвиг длины волны генерации от 406 до 425 nm за счет уменьшения оптических потерь лазера при увеличении его диаметра в пределах ...
Added: May 19, 2025
Бабичев А. В., Makhov I., Kryzhanovskaya N. et al., Письма в Журнал технической физики 2025 Т. 51 № 5 С. 41–44
Представлены результаты исследования расщепления мод шепчущей галереи в лазерах спектрального диапазона 930-950 nm на основе вертикального микрорезонатора. Использование распределенных брэгговских отражателей на основе чередующихся слоев Al0.2Ga0.8As/Al0.9Ga0.1As, не поглощающих на длине волны накачного лазера, позволило снизить величину пороговой мощности оптической накачки до 180 μW (для 3 μm-микролазера). Добротность микрорезонатора на пороге генерации для мод шепчущей галереи ...
Added: April 30, 2025