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Ultrasmall microdisk and microring lasers based on InAs/InGaAs/GaAs quantum dots
Nanoscale Research Letters. 2014. Vol. 9. No. 1. P. 657–657.
Ultrasmall microring and microdisk lasers with an asymmetric air/GaAs/Al0.98Ga0.02As waveguide and an active region based on InAs/InGaAs/GaAs quantum dots emitting around 1.3 μm were fabricated and studied. The diameter D of the microrings and microdisks was either 2 or 1.5 μm, and the inner diameter d of the microrings varied from 20% to 70% of the outer diameter D. The microring with D = 2 μm and d = 0.8 μm demonstrated a threshold pump power as low as 1.8 μW at room temperature. Lasing was observed up to 100°C owing to the use of quantum dots providing high confinement energy both for electrons and holes. Tuning spectral positions of the whispering gallery modes via changing the inner diameters of the microrings was demonstrated.
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Huang D., Chen Y., Luo X. et al., Chinese Journal of Physics 2026 Vol. 103 P. 1803–1814
Using self-consistent Bogoliubov-de Gennes calculations for kagome flakes framed by armchair
and flat edges, we observe a configuration-dependent spatial inhomogeneity of an 𝑠-wave superconducting
condensate. Specifically, at half-filling, the local pair potential is significantly enhanced
by up to 77.8% at edge centers and up to 148.9% at corners, subsequently boosting their
local critical temperatures by up to 13.5% and ...
Added: September 7, 2026
Marychev P., Shanenko A., Physical Review B: Condensed Matter and Materials Physics 2026 Vol. 114 No. 7 Article 074509
We investigate the effect of weak interband impurity scattering on the intertype (IT) domain between type-I and type-II superconductivity in diffusive two-band superconductors. Our results show that the significant broadening of the IT domain with increasing band diffusivity ratio, previously established in the absence of interband scattering, persists under weak interband scattering. However, depending on ...
Added: September 7, 2026
Denis K., Н. Новгород: Нижегородский государственный университет им. Н.И. Лобачевского, 2025.
В учебном пособии излагаются элементы теории и описание избранных экспериментальных результатов, полученных в активно развивающейся физике топологических изоляторов. Рассмотрены наиболее простые модели поверхностных и краевых состояний в двумерных и трёхмерных топологических изоляторах, их структура в магнитном поле, а также основы топологических методов для определения их свойств. Обсуждаются модели квантовых точек, формируемых в топологических изоляторах. Приведены ...
Added: September 6, 2026
Denis K., Звонков Б. Н., Вихрова О. В. et al., Физика твердого тела 2021 Т. 63 № 9 С. 1245–1252
Сочетанием методов МОС-гидридной эпитаксии и импульсного лазерного нанесения изготовлены гетеронаноструктуры InGaAs/GaAs со слоем (Ga, Mn)As на поверхности, и исследовано влияние воздействия импульсного эксимерного лазера (длина волны 248 nm, длительность импульса ~30 ns, плотность энергии в диапазоне 200-360 mJ/cm2) на их излучательные, структурные и гальваномагнитные свойства. При исследованиях использовалась спектроскопия фотолюминесценции, дополненная возможностью анализа поляризационных характеристик ...
Added: September 6, 2026
Воздействие импульсов эксимерного лазера на светоизлучающие InGaAs/GaAs-структуры с (Ga, Mn)As-слоем
Denis K., Вихрова О. В., Данилов Ю. А. et al., Физика твердого тела 2021 Т. 63 № 3 С. 346–355
Исследована возможность модифицирования лазерным отжигом свойств слоя (Ga, Mn)As, расположенного на поверхности квантово-размерной InGaAs/GaAs-структуры, с сохранением ее излучательных свойств. Для проведения исследований сочетанием методов МОС-гидридной эпитаксии и импульсного лазерного нанесения были изготовлены структуры с четырьмя квантовыми ямами InGaAs/GaAs, (содержание индия от 0.08 до 0.25), расположенными на различном расстоянии от слоя (Ga, Mn)As. В процессе исследований ...
Added: September 6, 2026
Denis K., Lavrukhina E. A., Journal of Physics: Conference Series 2021 Vol. 2103 Article 012201
A model of quasistationary states is constructed for the one-dimensional edge states propagating along the edge of a two-dimensional topological insulator based on HgTe/CdTe quantum well in the presence of magnetic barriers with finite transparency. The lifetimes of these quasistationary states are found analytically and numerically via different approaches including the solution of the stationary ...
Added: September 6, 2026
Denis K., Dorokhin M. V., Ved M. V. et al., Physical Review B: Condensed Matter and Materials Physics 2021 Vol. 104 No. 12 Article 125309
The GaAs/InGaAs quantum wells with a ferromagnetic δ〈Mn〉 layer in GaAs barrier demonstrate a set of interesting spin-related phenomena originating from Mn-hole interaction. One of such phenomena is a spin-memory effect which consists of Mn spin polarization induced by interaction with vicinity spin-polarized holes generated under the exposure by short circularly polarized light pulses. Here long Mn ...
Added: September 6, 2026
Denis K., Запруднов Н. А., Физика и техника полупроводников 2022 Т. 56 № 10 С. 973–978
Исследована динамика туннелирования и спина для дырочных состояний в двойной квантовой точке на основе GaAs при наличии сильного спин-орбитального взаимодействия и периодического электрического поля. Рассмотрены режимы туннелирования с переворотом спина в условиях "медленной" эволюции, при которой частота поля меньше остальных энергетических параметров стационарной части гамильтониана. Обнаружено, что в таких условиях туннелирование с переворотом спина может ...
Added: September 6, 2026
Denis K., Kalentyeva I. L., Vikhrova O. V. et al., Journal of Magnetism and Magnetic Materials 2022 Vol. 556 Article 169360
We have investigated the layers of the (Ga,Mn)As diluted magnetic semiconductor with the thickness in the range of 150 – 400 nm, which have been formed by the combination of the methods of a pulsed laser deposition and a post-growth pulsed laser annealing. It has been found that the laser annealing has a significant effect on the structural, ...
Added: September 6, 2026
Denis K., Konakov A. A., Lavrukhina E. A., Journal of Physics: Condensed Matter 2022 Vol. 34 Article 405302
A model of bound state formation from the delocalized edge states of 2D topological insulator (TI) is derived by considering the effects of magnetic barriers attached to the edge of the HgTe/CdTe quantum well. The resulting structure has a spatial form of 1D quantum dot (QD) with variable number of bound states depending on barrier ...
Added: September 6, 2026
Denis K., Studenikin S. A., Physical Review B: Condensed Matter and Materials Physics 2022 Vol. 106 No. 19 Article 195414
Single-spin state evolution induced by the Landau-Zener-Stückelberg-Majorana (LZSM) interference in a Zeeman-spit four-level system in a periodically driven double quantum dot is studied theoretically by the Floquet stroboscopic method. An interplay between spin-conserving and spin-flip tunneling processes with the electric dipole spin resonance (EDSR) that is induced in an individual dot and enhanced by the ...
Added: September 6, 2026
Denis K., Лаврухина Е. А., Тележников А. В., Физика и техника полупроводников 2023 Т. 57 № 7 С. 551–554
Разработана модель локализованных состояний в двойной квантовой точке на крае топологического изолятора на основе квантовой ямы HgTe/CdTe, сформированной тремя магнитными барьерами. Исследованы особенности энергетического спектра, плотности вероятности и спиновой плотности квантовых состояний в зависимости от ориентации векторов намагниченности магнитных барьеров. Изучена локализация волновых функций слева и справа от точки антикроссинга в спектре и сделан вывод ...
Added: September 6, 2026
Denis K., Bastrakova M. V., Munyaev V. O. et al., Physical Review B: Condensed Matter and Materials Physics 2023 Vol. 108 No. 20 Article 205404
Subharmonics of electric dipole spin resonance (EDSR) mediated by Landau-Zener-Stückelberg-Majorana tunneling transitions are studied numerically and analytically in a Zeeman-split four-level system with strong spin-orbit coupling that can be realized, for example, in a GaAs-based double quantum dot in a single-hole regime. The spin qubit is formed in one of the dots and the second ...
Added: September 6, 2026
Shabanov N., Kuricheva O., Kurbatova J. et al., / Series Working Papers SSRN "Department of Economics Ca’ Foscari University of Venice". 2026.
The carbon balance of an ecosystem is the difference between Gross Primary Productivity (GPP) and Ecosystem Respiration (Reco) as expressed by Net Ecosystem Exchange (NEE). While remote sensing retrievals of GPP have reached maturity, Reco estimation remains underexplored and ultimately cast bias on NEE. Here we present an end-to-end multi-scale analysis of the mechanism of ...
Added: August 21, 2026
Ponomarenko A., / Series Computer Science "arxiv.org". 2025.
This paper addresses the challenge of merging hierarchical navigable small world (HNSW) graphs, a critical operation for distributed systems, incremental indexing, and database compaction. We propose three algorithms for this task: Naive Graph Merge (NGM), Intra Graph Traversal Merge (IGTM), and Cross Graph Traversal Merge (CGTM). These algorithms differ in their approach to vertex selection ...
Added: July 30, 2026
Piontkovski D., / Series arXiv "math". 2026.
A noncommutative projective variety is defined, following Artin and Zhang, by a graded coherent algebra 𝐴. The category of coherent sheaves is then the quotient qgr(𝐴) of the category of finitely presented graded modules by the subcategory of torsion modules. We consider the categorical and polynomial entropies of the Serre twist, that is, of the ...
Added: June 23, 2026
Piontkovski D., / Series arXiv "math". 2025.
If a symmetric multilinear algebra is weakly nil, then it is Engel. This result may be regarded as an infinite-dimensional analogue of the well-known Jacobian theorem, which states that if a polynomial mapping has a polynomial inverse, then its Jacobian matrix is invertible. This refines a theorem of Gerstenhaber and partially answers a question posed ...
Added: June 23, 2026
Shipilov F., Barnyakov A., Ivanov A. et al., / Series Physics "arxiv.org". 2026.
A fast simulation of the detector response is a vital task in high-energy physics (HEP). Traditional Monte-Carlo methods form the backbone of modern particle physics simulation software but are computationally expensive. We present a machine-learning-based approach to fast simulation of the Focusing Aerogel Ring Imaging Cherenkov (FARICH) detector response. Given a particle track and momentum, ...
Added: May 19, 2026
Гущина В. А., / Series chemrxiv-2023-vpzhz-v2 "ChemRxiv". 2023.
All-inorganic perovskite CsPbBr3 and Cs4PbBr6 nanoparticles are being intensively studied due to their unique properties and wide range of applications; however, however, the nature of their optical properties is not yet fully understood due to the difficulty of synthesis of singlephase nanoparticles. In this article we describe the features of the synthesis of single-phase particles ...
Added: May 14, 2026
Derkacheva A., Sakirkina M., Kraev G. et al., /. 2026.
Comprehensive data on natural hazards and their consequences are crucial for effective for risk assessment, adaptation planning, and emergency response. However, many countries face challenges with fragmented, inconsistent, and inaccessible data, particularly regarding local-scale events. To address this data gap in Russia, we developed an end-to-end processing pipeline that scrapes news from various online sources, ...
Added: April 28, 2026
Pilé I., Deng Y., Shchur L., / Series arXiv "math". 2026. No. 2604.10254.
We investigate the spatial overlap of successive spin configurations in Markov chain Monte Carlo simulations using the local Metropolis algorithm and the Svendsen-Wang and Wolff cluster algorithms. We examine the dynamics of these algorithms for two models in different universality classes: the Ising model and the Potts model with three components. The overlap of two ...
Added: April 20, 2026
Gabdullin N., Androsov I., / Series Computer Science "arxiv.org". 2026.
Label prediction in neural networks (NNs) has O(n) complexity proportional to the number of classes. This holds true for classification using fully connected layers and cosine similarity with some set of class prototypes. In this paper we show that if NN latent space (LS) geometry is known and possesses specific properties, label prediction complexity can ...
Added: April 2, 2026
Sorokin K., Beketov M., Онучин А. et al., / arxiv.org. Серия cs.SI "Social and Information Networks ". 2025.
Community detection in complex networks is a fundamental problem, open to new approaches in various scientific settings. We introduce a novel community detection method, based on Ricci flow on graphs. Our technique iteratively updates edge weights (their metric lengths) according to their (combinatorial) Foster version of Ricci curvature computed from effective resistance distance between the ...
Added: January 15, 2026
Tatarinov D., Sapozhnikova E., Khmelevskaia D. et al., Chemical Communications 2024 Vol. 60 No. 93 P. 13730–13733
All-inorganic Pb–Cd mixed-cation halide perovskites have emerged as semiconductors exhibiting improved optical and optoelectronic properties. We establish a reliable correlation between photoluminescence and Cd content x in bulk CsPb1−xCdxBr3 compositions, propose pathways of photoexcited charge carrier dynamics in them, and show improved stability of lasing in whispering gallery mode microdisks. ...
Added: November 20, 2024