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Schmidt-mode analysis of quadrature entanglement in superpositions of two-mode multiphoton states
Physica Scripta. 2020. Vol. 95. No. 6. Article 064001.
M V Fedorov
Schmidt-decomposition formalism is proposed to be used for evaluation of the degree of
quadrature entanglement in two-mode multiphoton states. A series of examples are considered,
including analysis of the quadrature entanglement of the two-mode squeezed vacuum. Singlemode
and two-mode coherent states with stochastic phases are analyzed by the same method
though in this case features of quadrature states are interpreted in terms of decoherence rather
than entanglement.
Polkin A., Skvortsov M., Physical Review B: Condensed Matter and Materials Physics 2026 Vol. 113 Article 174516
We develop a full microscopic theory for the optical conductivity 𝜎(𝜔) of a dirty current-carrying superconductor. Within the Keldysh sigma model formalism, we obtain the general analytical expression for 𝜎(𝜔), applicable for arbitrary frequency 𝜔, temperature 𝑇, and dc supercurrent 𝐼. In addition to altering the usual Mattis-Bardeen conductivity 𝜎1(𝜔), a finite supercurrent introduces two new contributions: 𝜎qp2(𝜔) from quasiparticle redistribution and 𝜎SH2(𝜔) from the amplitude ...
Added: June 25, 2026
Skvortsov M., Artem Polkin, Physical Review B: Condensed Matter and Materials Physics 2026 Vol. 113 No. 10 Article 100502
A dissipationless supercurrent state in superconductors can be destroyed by thermal fluctuations. Thermally activated phase slips provide a finite resistance of the sample and are responsible for dark counts in superconducting single-photon detectors. The activation barrier for a phase slip is determined by a space-dependent saddle-point (instanton) configuration of the order parameter. In the one-dimensional ...
Added: June 25, 2026
Деменев А. А., Терешко С. Н., Гиппиус Н А et al., Известия РАН. Серия физическая Россия 2025 Т. 89 № 2 С. 265–273
The authors study the temporal evolution of polarized spectra of emissions from spinor exciton‒
polariton condensates in double tunnel-coupled potential traps inside a high-Q GaAs/AlAs microcavity
at 2 K upon resonance laser pumping with picosecond pulses at times of up to 1.5 ns. The period of the condensates’
spin relaxation in a double trap is estimated as τs ...
Added: June 23, 2026
Абрамов-Максимов В. Е., И.А. Бакунина, Геомагнетизм и аэрономия 2026 Т. 66 № 3 С. 515–529
Проанализировано 8 вспышечных событий по данным многочастотных наблюдений сети радиотелескопов Radio Solar Telescope Network. Целью анализа было выявление предвестников солнечных вспышек. В семи рассмотренных случаях выявлены предвспышечные квазипериодические флуктуации радиоизлучения. Сделанная по вейвлет-спектрам оценка квазипериодов дает в большинстве случаев значения 40–50 сек. В одном событии с большой вспышкой класса M8.0 квазипериодические флуктуации не проявились. В ...
Added: June 22, 2026
И.А. Бакунина, В.Ф. М., А.В. Ш. et al., Геомагнетизм и аэрономия 2025 Т. 65 № 9 С. 1363–1373
Рассмотрена связь особенностей положения и ориентации магнитных жгутов в активной области (АО) с источниками микроволнового (17 ГГц) излучения и излучения в крайнем ультрафиолетовом диапазоне (EUV) при возникновении эруптивных вспышек, сопровождающихся корональными выбросами массы, и вспышек с "запертой" эрупцией. Приведены примеры эруптивных событий, демонстрирующие пространственное совпадение микроволновых источников с расположением магнитных жгутов в АО, восстановленных при ...
Added: June 22, 2026
Г. Г. Бондаренко, Кристя В. И., Савичкин Д. О. et al., Поверхность. Рентгеновские, синхротронные и нейтронные исследования 2026 № 4 С. 29–36
Сформулирована модель тлеющего газового разряда в смеси аргона и паров ртути при наличии
на поверхности катода тонкой диэлектрической пленки. Рассчитаны зависимости характеристик
разряда от температуры в интервале ее изменения, в котором заметный вклад в ионизацию
рабочей газовой смеси дает ионизация атомов ртути метастабильными возбужденными атомами
аргона (реакция Пеннинга). Показано, что в случае катода без диэлектрической пленки при
повышении температуры до ...
Added: June 20, 2026
Chertenkov V. I., Shchur L., Lobachevskii Journal of Mathematics 2026 Vol. 47 No. 2 P. 720–727
Supervised machine learning is successfully applied to the study of critical phenomena and allows us to obtain a numerical estimate of the phase transition temperature and the correlation length exponent. We discuss the influence of possible systematic errors, as well as statistical errors, on the accuracy of such numerical estimates. Errors in the training and ...
Added: June 16, 2026
Батурин А. С., Гаврилов В. Р., Иванов А. В. et al., Измерительная техника 2026 Т. 75 № 2 С. 14–28
28 декабря 2025 года Всероссийскому научно-исследовательскому институту оптико-физических измерений (ВНИИОФИ) исполнилось 60 лет. За прошедшие десятилетия институт выполнил значительное количество научных исследований, разработал и поставил потребителям тысячи высокоточных средств оптико-физических измерений (включая эталонное оборудование). В статье представлены наиболее значимые для метрологического обеспечения оптико-физических измерений результаты научно-исследовательских работ, выполненных ВНИИОФИ за период 2016–2025 гг. ...
Added: June 15, 2026
Вишняков Г. Н., Левина Э. Ю., Minaev V., Измерительная техника 2025 Т. 74 № 2 С. 20–27
Качество формируемого оптической системой изображения определяется её частотно-контрастной характеристикой или коэффициентами передачи модуляции на различных пространственных частотах. Для обеспечения единства измерений коэффициентов передачи модуляции и создания эталонной базы по воспроизведению, хранению и передаче единицы коэффициента передачи модуляции усовершенствован Государственный первичный эталон единиц оптической силы очковой оптики ГЭТ 205-2013 в части воспроизведения единицы коэффициентов передачи модуляции ...
Added: June 15, 2026
Filippova A. V., Yurchenko N. Y., Smirnov S. A. et al., Journal of Alloys and Compounds 2026 No. 1074 Article 189162
This study investigates the effects of post-processing heat treatment at 300–500 °C on the microstructure, hardness, and tensile properties of laser powder bed fusion (PBF-LB) processed Al-bronze processed with energy densities (ED) in the range of 125–938 J/mm3. In the as-printed state, sharp needle-like α + β′ laths form at lower ED whereas with increasing ED, the β′ ...
Added: June 12, 2026
Спонтанное образование скин-слоя в воде с деформацией ОН-полосы КР вкладом компоненты льда 3200 см-1
Першин С. М., Степанов Е. В., Артемова Д. Г. et al., Письма в Журнал экспериментальной и теоретической физики 2026 Т. 123 № 6 С. 383–390
Открыто спонтанное образование в течение 4 ч скин-слоя дистиллированной воды толщиной до 3 мм при комнатной температуре с новыми свойствами. Обнаружены деформация ОН-полосы комбинационного рассеяния вкладом компоненты льда ( 3200 см-1), снижение коэффициента упругого рассеяния и его флуктуаций, а также увеличение на 20 капиллярах. Восстановление слоя после обогащения воздухом в результате перемешивания указывает на стабильность ...
Added: June 8, 2026
Springer, 2026.
The book presents the proceedings of the 13th International Conference on Frontiers of Intelligent Computing: Theory and Applications (FICTA 2024), held at Intelligent Systems Research Group (ISRG), London Metropolitan University, London, United Kingdom, during June 6–7, 2025. Researchers, scientists, engineers and practitioners exchange new ideas and experiences in the domain of intelligent computing theories with ...
Added: June 8, 2026
N.S. Artekha, D.R. Shklyar, Physics of Plasmas 2026 Vol. 33 No. 6 Article 062105
The peculiarities of resonant interaction between slow extraordinary (SE) waves and relativistic electrons have been studied. General equations of motion of relativistic electrons in the field of SE wave and a uniform ambient magnetic field are derived. Conditions of applicability of the isolated resonance approximation are elucidated. In this approximation, the equations of motion are reduced to one-dimensional set of ...
Added: June 6, 2026
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
A. V. Pereskokov, Journal of Mathematical Sciences 2025 Vol. 291 No. 4 P. 544–553
We study the eigenvalue problem for a perturbed resonance oscillator. We find asymptotic
expansions of coherent states of the algebra su(2). We show that the asymptotic
eigenfunctions are localized near a circle and construct an expansion of asymptotic eigenfunctions
near this circle. ...
Added: December 7, 2025
Lankin A. V., Norman G., Russian Journal of Physical Chemistry A 2025 Vol. 99 No. 11 P. 2833–2904
We present the current state of quantum mechanics, the prospects for its development, and the
strengthening of its influence on scientific and technological progress. We look at quantum mechanics from
four perspectives. The first perspective astonished physicists already with the advent of quantum mechanics—
it is (1) a new way of looking at the world. Over the course ...
Added: November 20, 2025
K S Kravtsov, Laser Physics Letters 2023 Vol. 20 No. 8 Article 085203
The paper analyzes security aspects of practical entanglement-based quantum key distribution
(QKD), namely, BBM92 or entanglement-based BB84 protocol. Similar to prepare-and-measure
QKD protocols, practical implementations of the entanglement-based QKD have to rely upon nonideal
photon sources. A typical solution for entanglement generation is the spontaneous parametric
down-conversion. However, this process creates not only single photon pairs, but also quantum
states ...
Added: March 12, 2024
Vinetskaya P. M., Kravtsov K. S., Borshchevskaia N. A. et al., Laser Physics Letters 2023 Vol. 20 No. 5 Article 055201
Entangled quantum key distribution (QKD) is a promising way to generate pairs of unconditionally secret keys. In this paper we review possible realizations of entanglement-based QKD and assess their feasibility in terms of implementation complexity and provided security. We also propose a novel active basis choice approach that enables to use only one single-photon detector ...
Added: March 12, 2024
Seidelman T., Schimpf C., Bracht T. et al., Physical Review Letters 2022 Vol. 129 No. 19 Article 193604
Entangled photon pairs are key to many novel applications in quantum technologies. Semiconductor quantum dots can be used as sources of on-demand, highly entangled photons. The fidelity to a fixed maximally entangled state is limited by the excitonic fine-structure splitting. This work demonstrates that, even if this splitting is absent, the degree of entanglement cannot ...
Added: December 1, 2022
Pashin D., Bastrakova M., Arkady Satanin et al., Sensors 2022 Vol. 22 No. 17 Article 6580
We study bifurcation behavior of a high-quality (high-Q) Josephson oscillator coupled to a superconducting qubit. It is shown that the probability of capture into the state of dynamic equilibrium is sensitive to qubit states. On this basis we present a new measurement method for the superposition state of a qubit due to its influence on ...
Added: October 26, 2022
В. П. Спиридонов, Теоретическая и математическая физика 2022 Т. 212 № 3 С. 403–413
We describe a family of quantum states of the Schrödinger cat type as superpositions of the harmonic oscillator coherent states with coefficients defined by the quadratic Gauss sums. These states emerge as eigenfunctions of the lowering operators obtained after canonical transformations of the Heisenberg–Weyl algebra associated with the ordinary and fractional Fourier transformations. The first member of this family is given by the well ...
Added: August 30, 2022