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Role of arsenic vapor pressure in transformation of InAs quantum dots during overgrowth by a GaAs capping layer
Journal of Luminescence. 2024. Vol. 272. Article 120621.
Balakirev S., Alexey Nadtochiy, Natalia Kryzhanovskaya, Kirichenko D., Chernenko N., Shandyba N., Sergey Komarov, Anna Dragunova, Alexey Zhukov, Solodovnik M.
The results of a study of the optical properties of self-assembled InAs/GaAs (001) quantum dots (QDs) overgrown under different arsenic pressures, obtained using photoluminescence (PL) and PL excitation spectroscopy, are presented. If the arsenic pressure during overgrowth is low (2.5·10−6 Pa), a series of pronounced QD-related peaks is observed in the 77-K PL spectrum over a 200-meV broad spectral interval with the brightest one located at 1.37 eV. With increasing arsenic pressure, the PL spectrum becomes smoother and is red-shifted to 1.16 eV at 1·10−5 Pa and to 1.26 eV at 3·10−5 Pa. We explain this behavior in terms of enhanced QD decomposition, the mechanism of which is strongly dependent on the arsenic deficiency or excess during the overgrowth process, determined by the arsenic pressure. Supported by the analysis of the wetting layer luminescence, we also conclude that the total indium content in the QD layer decreases with decreasing arsenic pressure during the overgrowth. This study reveals an essential role of the arsenic pressure in the overgrowth of InAs QDs.
Shilov A. L., Elesin L., Kravtsov M. et al., Nature Communications 2026 Vol. 17 No. 1 Article 9734
Identifying the microscopic processes limiting conductivity is essential for understanding correlated quantum materials. In twisted bilayer graphene, metallic resistivity follows ρ ~ Tα with widely varying α, fueling competing interpretations from phonon-limited transport and umklapp scattering to strange metallicity and heavy-fermion renormalization. Here, we use terahertz excitation to selectively heat electrons while keeping the lattice cold, separating ...
Added: September 20, 2026
Копьев А., JETP Letters 2026 Vol. 123 No. 5 P. 310–316
The incompressible three-dimensional Euler equations develop very thin pancake-like regions of exponen tially increasing vorticity. The characteristic thickness of such regions decreases exponentially with time, while the other two dimensions do not change considerably, making the flow near each pancake strongly anisotropic. The pancakes emerge in increasing number with time, which may enhance the anisotropy ...
Added: September 18, 2026
Захаров А. В., Düven H., Capar M. I., Physics Letters A 2026 No. 576 Article 131388
Molecular dynamics simulations were carried out to study the structural properties of nematic pentyl
cyanobiphenyl (5CB) and pentyloxy cyanobiphenyl (5OCB) liquid crystals (LCs) doped with gold nanoparti
cles (GNPs) of different numbers, shapes and sizes. The spherical GNPs of two different radii and rod-like have
been doped in 5CB and 5OCB cyanobiphenyl liquid crystals. In order to describe ...
Added: September 17, 2026
Andreev D. V., Kornev S. A., Bondarenko G.G. et al., Inorganic Materials: Applied Research 2026 Vol. 17 No. 5 P. 1226–1230
Comparative studies are carried out to investigate high-field charge degradation effects in the gate
dielectric of metal—insulator—semiconductor (MIS) structures with aluminum and polysilicon gates.
Charging phenomena in MIS structures are explored using high-field electron injection into the dielectric
under conditions of gradually increasing voltage current density, with periodic short-term switching to a measurement
mode at a constant low injection ...
Added: September 15, 2026
Poddiakov A., / Series Social Science Research Network "Social Science Research Network". 2026. No. 7437658.
Clarity of knowledge and reasoning is necessary in many cases. Yet vagueness in scientific thinking related to surprise, curiosity, "ability to engage with not-knowing" (de Freitas) and abductive reasoning is also a crucially important source of scientific creativity which supplements combinatorial logic when dealing with the already known. Starting from studies by C. S. Peirce ...
Added: September 15, 2026
Water confined in heterogeneous clay–quartz pores: Structure and dynamics from atomistic simulations
Glushak A., Tararushkin E., Smirnov G., Colloids and Surfaces A: Physicochemical and Engineering Aspects 2027 Vol. 752 Article 141756
The molecular-scale behavior of water in heterogeneous clay–quartz systems is critical for understanding cementation processes in natural soils and compacted bentonite, which is crucial for oil recovery and nuclear waste disposal barriers construction. Here we investigate how heterogeneity of mixed Na-montmorillonite and α-quartz surfaces affect water structure and dynamics in nanopores of 2.5 to 60 Å ...
Added: September 15, 2026
Bochkin G., Doronin S., Fel’dman E. et al., Lobachevskii Journal of Mathematics 2024 Vol. 45 No. 3 P. 1188–1207
We consider the remote state restoring and perfect transfer of the zero-order coherence matrix (PTZ) in a spin system governed by the XXZ-Hamiltonian conserving the excitation number. The restoring tool is represented by several nonzero Larmor frequencies in the Hamiltonian. To simplify the analysis we use two approximating models including either step-wise or pulse-type time-dependence ...
Added: September 14, 2026
Fel’dman E. B., Lazarev I., Pechen A. N. et al., Quantum Information Processing 2026 Vol. 25 Article 121
We consider the state-restoring protocol based on the controlled interaction of a linear chain with environment through incoherent control by the specially adjusted step-wise time-dependent Lindblad operators. We show that the best restoring result (maximal scale factors in the restored state) corresponds to the symmetrical Lindblad equation. (0, 1)-excitation dynamics is considered numerically, and restoring ...
Added: September 14, 2026
Li S., Hu J., Lazarev I. et al., Annals of Physics 2026 Vol. 494 Article 170618
The distribution of entanglement is a crucial task for quantum communication towards realizing a globe-spanning quantum internet. Recently, a protocol for deterministic long-distance distribution of macroscopic entanglement over a network of ensembles of qubits was introduced (Pyrkov et al., 2025). It was shown that this protocol allows for the propagation of macroscopic amounts of entanglement ...
Added: September 14, 2026
Pyrkov A., Lazarev I., Byrnes T., Advanced Quantum Technologies 2025 Article 2400524
Distributing long-distance entanglement is a fundamental goal that is necessary for a variety of tasks such as quantum communication, distributed quantum computing, and quantum metrology. Currently quantum repeater schemes typically aim to distribute one ebit at a time, the equivalent of one Bell pair's worth of entanglement. Here, a scheme is presented to distribute a ...
Added: September 14, 2026
I. D. Lazarev, Narozniak M., Byrnes T. et al., Physical Review A: Atomic, Molecular, and Optical physics 2025 Vol. 111 No. 012416 Article 012416
Unsupervised machine learning is one of the main techniques employed in artificial intelligence. We introduce an algorithm for quantum-assisted unsupervised data clustering using the self-organizing feature map, a type of artificial neural network. The complexity of our algorithm scales as 𝑂(𝐿𝑁), in comparison to the classical case which scales as 𝑂(𝐿𝑀𝑁), where 𝑁 is the ...
Added: September 14, 2026
Борщевский А. Я., Physical Chemistry Chemical Physics 2025 Vol. 27 No. 9 P. 4793–4803
Through the consistent application of quantum statistical thermodynamics, functions of isothermal mixing of real rarefied gases and quantum gases in states of varying degrees of degeneracy are obtained. The reasons for the emergence and resolution of the “Gibbs paradox” and other “paradoxes” are analyzed. Numerical calculations of entropy and pressure jumps were performed using the ...
Added: September 14, 2026
D.L. Gurina, Fashchevsky K. A., Oparin R. D. et al., Surfaces and Interfaces 2026 Vol. 98 Article 110545
In this work, we combine experimental characterization and molecular dynamics (MD) simulations to elucidate the molecular mechanisms governing the impregnation of mefenamic acid (MFA) into nanocrystalline cellulose (NCC) aerogels. NCC aerogels were impregnated with MFA in scCO2, and low-temperature nitrogen adsorption revealed a concentration-dependent decrease in surface area, pore volume, and pore size, with an ...
Added: September 8, 2026
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
P. M. Marychev, A. A. Shanenko, 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
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
V.I. Voitovich, I.S. Makhov, Andryushkin V. V. et al., Journal of Luminescence 2026 Vol. 295 Article 121936
We report on a comparative study of the optical and structural properties of short-period superlattices (SPSLs) based on digital ternary InGaAs/InAlAs alloys and their counterparts with quaternary InGaAlAs barriers, both grown on InP substrates and emitting in the 1.3 μm wavelength range. The heterostructures were grown by molecular beam epitaxy and analyzed using photoluminescence spectroscopy ...
Added: July 8, 2026
Sharov V., Pavlov A., Eliseyev I. et al., Advanced Optical Materials 2025 Vol. 13 No. 30 Article e01821
Strain engineering is a powerful tool for the development of nanostructured semiconductor devices. In this work, the effect of high external elastic strain is investigated on the photoluminescence of GaN nanowires (NWs). Individual horizontal NWs are strained to bending strains up to 2.2% using an atomic force microscope (AFM) probe. Novel nanomanipulation techniques for mechanical ...
Added: November 12, 2025
Anna Obraztsova, Ivan Makhov, Ivan Melnichenko et al., Journal of Lightwave Technology 2025 Vol. 43 No. 15 P. 7278–7284
Spectral characteristics of quantum dot (QD) microdisk lasers under spatially inhomogeneous optical excitation are
investigated. By varying the position and size of the continuous wave excitation spot over the laser cavity, we demonstrate controllable selection and switching of lasing whispering gallery modes (WGMs) at room temperature. Experimental results show that shifting the excitation spot across the ...
Added: September 5, 2025
Balakirev S. V., Makhov I., Kirichenko D. V. et al., Optical Materials 2025 Vol. 163 Article 116964
We reveal a strong dependence of optical properties of InAs quantum dots (QDs) on the As/Ga flux ratio used
during the overgrowth with a low-temperature GaAs layer. Evaluating various characteristics of the photoluminescence
spectra, we determine an optimal As/Ga flux ratio which allows formation of QDs emitting at the
longest wavelengths, with the highest intensity and the largest ...
Added: April 17, 2025
P. S. Berezhnoy, Koreyev A. S., A. B. Van'kov et al., Physical Review B: Condensed Matter and Materials Physics 2024 Vol. 110 No. 23 Article 235306
Collective spin excitations were utilized to probe many-particle energies of strongly correlated quantum Hall
ferromagnets (FMs) at 1/3< ν < 1. For this purpose, experiments on inelastic light scattering and polarized
photoluminescence (PL) were performed on a MgZnO/ZnO heterostructure, containing a high-mobility two dimensional
electron system with theWigner-Seitz parameter rs ≈ 11. The dispersion of the Larmor spin exciton ...
Added: January 14, 2025
Koreyev A. S., P.S. Berezhnoy, Gorbunov A. V. et al., Physical Review B: Condensed Matter and Materials Physics 2024 Vol. 110 No. 16 Article 165417
The phase diagram of the “gas-magnetoexciton condensate” transition of an excited two-dimensional electron
system placed in a quantizing magnetic field has been constructed in the “temperature-laser excitation power
density” coordinates. Based on the experimental data, we can conclude that the condensate is a collective,
incompressible in real space, excited state of a quantum Hall insulator. ...
Added: January 10, 2025