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Decay of metastable excited states of two qubits in a waveguide
Physical Review A: Atomic, Molecular, and Optical physics. 2014. Vol. 90. P. 063829 (1)–063829 (12).
Redchenko E. S., Yudson V.I.
For a system of two spatially separated qubits (two-level atoms) coupled to a one-dimensional waveguide
we have described the time evolution of singly or doubly excited states of the atomic subsystem. When the
interatomic distance l takes special (“resonant” or “antiresonant”) values, the singly excited system of resonant
atoms can form metastable (dark) states. If l slightly deviates from one of the special values or the atomic
frequencies do not coincide, the dark states slowly decay and we have calculated the decay rate. Also, we have
found that the doubly excited state of two resonant atoms located at the special positions does not completely
decay but, with a finite probability, can evolve (with the emission of a single photon) to one of the metastable
singly excited states. Metastable states of pairs of qubits may find applications (e.g., as memory elements) in
information processing or as detectors sensitive to external perturbations.
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
Arutyunov K., JIANG1 Q., FANG J. et al., Science China Information Sciences 2026 Vol. 69 No. 6 P. 1–11
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., Shchur L. et al., Physica A: Statistical Mechanics and its Applications 2026 Vol. 696 P. 1–13
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 ...
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Melentiev P. N., Калмыков А. С., Гритченко А. С. et al., Успехи физических наук 2024 Т. 194 № 11 С. 1130–1145
Представлен краткий обзор достигнутого уровня оптических методов детектирования единичных молекул в биомедицинских приложениях. Показано, что регистрация флуоресценции единичных молекул красителей, ковалентно связанных с антителами (биомолекулами), совместно с использованием современных методов нанофотоники может быть применена для решения различных задач в биологии и медицине: визуализации биомолекул, токсинов, вирусных частиц, определения ультранизких концентраций аналитов напрямую во взятой пробе, ...
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Antsiferov P.S., Stepanov L.V., Matiukhin N. D., Review of Scientific Instruments 2025 Vol. 96 No. 12 Article 123506
The article presents the discharge plasma based source of extreme ultraviolet (EUV) radiation. The discharge circuit has been driven by means of stripe line storage with working voltage 10.5 kV. The main feature of the proposed source is that plasma electrons acquire the energy, necessary for the production of multiply charged ions with ionization potentials ...
Added: May 20, 2026
Анциферов П. С., Степанов Л. В., Матюхин Н. Д., Оптика и спектроскопия 2026 Т. 134 № 2 С. 214–218
Сообщено о разработке системы регистрации спектров на ПЗС-линейке для уникального ВУФ спектрометра, построенного на основе сферической дифракционной решетки с радиусом 6.65 m. Была использована линейка HAMAMATSU S11156-2048-02, которая устанавливалась по касательной к окружности Роуланда с возможностью механического перемещения для сканирования спектра. Были получены спектрограммы в диапазоне длин волн 2130-2270 Angstrem. Описана методика сшивки регистрируемых спектральных ...
Added: May 20, 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
Malinovsky A. M., Пилипенко С. В., Mikhalchenko A. O. et al., Astronomy Reports 2026 Vol. 70 P. 1–6
Radiation from rotational transitions of CO molecules in distant galaxies creates a chaotic background with an intensity reaching 1000 Jy/sr at a wavelength of approximately 1 mm. This background will pose a serious problem, when measuring spectral distortions of the cosmic microwave background, in particular, the mu-distortion, which presumably has an intensity of less than ...
Added: May 19, 2026
Kaveev A. K., Fedorov V. V., Pavlov A. V. et al., Journal of Materials Chemistry C 2026 Vol. 14 No. 7 P. 2697–2705
Bismuth nanostructures represent a promising material platform for semiconductor nanooptoelectronics and colorimetry owing to the multi-colored light reflection and quantum confinement. In this work, we study the photoluminescent properties of bismuth nanostructures grown using molecular beam epitaxy on the planar CaF2/Si(111) surface. We demonstrate the different surface morphologies of Bi, ranging from planar films obtained ...
Added: May 19, 2026
Pavlova T., V.M. Shevlyuga (Шевлюга В. М., Applied Surface Science 2026 Vol. 736 P. 166813–166813
The objective of miniaturizing doped areas in silicon, with the ultimate goal of achieving atomic-precision doping, requires a fundamental understanding of the dopant incorporation process at the atomic level. We present a combined scanning tunneling microscopy (STM) and density functional theory (DFT) investigation of single phosphorus atom incorporation into the Si(100) surface. Phosphorus was supplied ...
Added: May 19, 2026
Pasternak D., Romshin A., Khmelnitsky Р. et al., Carbon 2026 Vol. 256 Article 121655
A single-photon source (SPS) is a key component required for quantum communication devices. We report the
discovery of bright diamond-based SPS created by nature. It is shown that narrow (≤2 nm) lines observed in the
500-800 nm range in photoluminescence (PL) spectra of the surface layer of untreated Yakut diamonds rich in
nitrogen and hydrogen are linked to ...
Added: May 19, 2026
A.M. Smirnov, Kurtina D. A., Saitov S. R. et al., Optical Materials: X 2026 Vol. 30 Article 100441
Chiral semiconductor nanostructures and nanoparticles are promising materials for applications in biological sensing, enantioselective separation, photonics, and spin-polarized devices. Here we performed a detailed analysis of optical properties of chiral CdSe nanoplatelets with thickness of 2 and 3 monolayers (ML) with Nacetyl-L-cysteine ligands. We studied the absorption spectra peculiarities, analyzed time-resolved photoluminescence and investigated circular ...
Added: May 18, 2026
Saitov S. R., Saidzhonov B. M., Vasiliev R. B. et al., Journal of Applied Physics 2026 Vol. 139 No. 18 Article 185702
This work presents a comprehensive investigation into the temperature-dependent thermally stimulated conductivity and photoconductivity of vacuum-annealed thin films based on core–shell CdSe/CdS nanoplatelets passivated with oleic acid ligands. Controlled thermal annealing under vacuum conditions leads to a substantial increase in both dark and photoinduced conductivity, which is primarily attributed to partial desorption of the ligands. ...
Added: May 18, 2026
Масютин Д. А., Moiseev E., Komarov S. et al., Письма в Журнал технической физики 2026 Т. 52 № 7 С. 27–30
Исследованы инжекционные полупроводниковые микролазеры с кольцевым резонатором радиусом 15 мкм с несимметричным расположением внутреннего отверстия резонатора. Показано, что асимметрия обеспечивает формирование в диаграмме направленности двух лепестков излучения, разориентированных на 50° относительно оси смещения внутреннего отверстия. Измеренная добротность резонаторов сопоставима с добротностью дисковых резонаторов и находится на уровне ∼ 10^6. ...
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Rathish S., Andrey S. Vasenko, Thazhathenair A. et al., The Journal of Physical Chemistry Letters 2026 Vol. 17 No. 18 P. 5386–5394
We demonstrate and rationalize the effect of Au nanoparticles (NPs) on the hierarchical g-C3N4/CeO2 heterojunction. g-C3N4/CeO2 decorated with monodispersed plasmonic Au NPs was synthesized. Detailed analyses showed that CeO2 nanocubes and monodispersed Au NPs were evenly distributed over the 2D g-C3N4 surface, forming a robust interface enriched with abundant active sites. The structure enabled efficient separation of photogenerated charge ...
Added: May 16, 2026
Paul R., Das A., Sharma N. et al., Colloids and Surfaces A: Physicochemical and Engineering Aspects 2026 Vol. 728 Article 138830
Niobium-doped TiO2 (Nb-TiO2), demonstrates dual functionality as an efficient photocatalyst for dye degradation and a promising photoelectrocatalyst for water oxidation. Nb incorporation via a facile hydrothermal method was confirmed by XRD (Rietveld refinement), XPS, TEM, FT-IR, Raman, and BET analyses, indicating successful lattice doping and structural modification. Photocatalytic dye degradation experiments were conducted using a model ...
Added: May 16, 2026
-, 2025.
12-th International School and Conference “Saint Petersburg OPEN
2025” on Optoelectronics, Photonics, Engineering and Nanostructures
carries on the tradition of annual conferences and schools organized at
St Petersburg Academic University for students, PhD students and young
scientists. More detailed information on the School and Conference is
presented on https://spb.hse.ru/spbopen/
The Book of Abstracts includes abstracts of contributed works accepted
for presentation at ...
Added: October 29, 2025
Кузьминых И. О., Kuzin A., Флоря И. Н. et al., Нано- и микросистемная техника 2025 Т. 27 № 4 С. 184–194
В работе рассмотрены основные варианты детектирования водорода, а также приведены требования, которые предъявляются к сенсорам водорода. Проанализированы преимущества и недостатки существующих решений по детектированию водорода и проведен сравнительный анализ основных метрик коммерчески доступных сенсоров водорода. Было установлено, что оптические сенсоры преодолевают основную проблему существующих сенсоров – использование электрического тока в чувствительной зоне сенсоров. Данная обзорная ...
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K.V. Shein, A.N. Lyubchak, Zharkova E. et al., St. Petersburg Polytechnical University Journal: Physics and Mathematics 2024 Vol. 17 No. 3.2 P. 241–245
Photonic integrated circuits (PIC) represent a promising platform for applications in the field of quantum technologies, such as quantum computing and cryptography. One of the key components for these applications is detectors based on thin superconducting films. Nevertheless, fabricating thin detectors atop a waveguide utilizing conventional superconducting materials acquired through magnetron sputtering presents a multifaceted ...
Added: November 5, 2024
St. Petersburg: IEEE, 2022.
The 2023 International Conference on Electrical Engineering and Photonics (EExPolytech-2023) was held at Peter the Great St. Petersburg Polytechnic University, St. Petersburg, Russia, October 19-20, 2023. The main goal of the conference was to bring together specialists in closely related fields like electronics engineering, signal processing, materials science and photonics thus promoting fluent knowledge dissemination. ...
Added: May 31, 2024
Vozhakov V., Bastrakova M. V., Klenov N. et al., QUANTUM SCIENCE AND TECHNOLOGY 2023 Vol. 8 No. 3 Article 035024
The development of quantum computers based on superconductors requires the improvement of the qubit state control approach aimed at the increase of the hardware energy efficiency. A promising solution to this problem is the use of superconducting digital circuits operating with single-flux-quantum (SFQ) pulses, moving the qubit control system into the cold chamber. However, the ...
Added: June 19, 2023
Смирнов И. А., Черкесова Л. В., Разумов П. В. et al., Современные наукоемкие технологии 2019 Т. 1 С. 114–118
The proposed article compares the quantum factorization algorithm of Peter Shor and the factorization algorithm of the ?-John Pollard method. As is well known, the quantum algorithm for factoring Shor consists of classical and quantum parts. In the classical part, it is proposed to use the Euclidean algorithm to find the greatest common divisor of ...
Added: May 10, 2023