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Semion formalism for spin and qubit systems: Non-Markovian treatment
Physical Review A: Atomic, Molecular, and Optical physics. 2020. Vol. 102. No. 3. Article 042224.
Elistratov A., Remizov S., Lozovik Y.
Using semion substitution for spin variables we perform an ab initio derivation of effective action for an open quantum two-level system . For this purpose, we introduce, by using the Hubbard-Stratonovich transformation a two-time complex quantum field which average value plays the role of the Green's function for the spin variables. The field thus introduced allows us to develop a diagram technique in a standard way. The proposed formalism is used to study a spin embedded into an Ohmic reservoir as an example of the spin-boson model. Non-Markovian effects in this system are analyzed.
Dmitriev A., Kornilov V., Batienkov R., Lecture Notes in Civil Engineering 2026 Vol. 886 P. 249–255
Numerous studies have provided compelling evidence that the probability distribution of avalanche sizes follows a power law, and that 1/f noise is present in the stochastic dynamics of landslides. We present a theoretical explanation of these phenomena within the framework of self-organized criticality theory, proposing a discrete-time model in the form of a sandpile cellular ...
Added: October 13, 2026
Dmitriev A., Shulman I., Lebedev A., Studies in Computational Intelligence 2026 Vol. 1265 P. 266–273
A discrete-time model is presented for the self-organization of the X/Twitter social network to the edge of a phase transition, characterized by avalanche-like propagation of information in the network. The model is based on the analogy between the critical dynamics of the X social network and sandpile cellular automata with Manna rule on the Chung-Lu ...
Added: October 13, 2026
Arutyunov K., Kharitonov I. A., Petrosyants K. O., JETP Letters 2026 Vol. 124 No. 6 P. 1–16
Superconducting properties of metallic micro- and nanowires can be entirely different from those of bulk superconductors. Of particular interest is the nonequilibrium current-induced state of a quasi-one-dimensional superconducting channel. The most interesting phenomenon here is the stepped I–V characteristic, explained by a process known as phase slip center activation. If the origin of such step-like ...
Added: October 13, 2026
Makarov D. M., Kalikin N., Fashchevsky K. A. et al., Electrochimica Acta 2026 Vol. 579 Article 150159
Machine learning (ML) has become a powerful tool for accelerating the development of carbon-based supercapacitors;
however, most published models assume that a single predictive framework can describe both conventional
porous carbons and hybrid carbon electrodes. Here, we test this assumption using a comprehensive
benchmark dataset and an extended literature-curated dataset enriched with synthesis- and electrolyte-related
descriptors. Three ML algorithms ...
Added: October 13, 2026
Махлуф М., Ozhegov R., Elezov M. et al., Фотоника 2026 Vol. 20 No. 6 P. 414–423
This paper compares the ranging precision of direct time-of-flight (dToF) and non-line-of-sight (NLOS) LiDAR architectures, both using a superconducting nanowire single-photon detector (SNSPD). Both systems operate at 1550 nm with a 50 ps pulsed laser and time-correlated single-photon counting (TCSPC). The dToF configuration achieved approximately 100 µm precision at 10 m, while the NLOS configuration achieved 500 µm precision for ...
Added: October 12, 2026
Singapore: Springer, 2026.
This volume presents the Proceedings of the 34th IUPAP Conference on Computational Physics (CCP2023), held in Kobe, Japan on August 4–8, 2023. It offers a collection of peer-reviewed articles that highlight recent developments in computational and simulation research across various areas of physics. Key topics include the use of data science, quantum computing, and machine ...
Added: October 12, 2026
Goncharov A., Chibisov A., Advanced Theory and Simulations 2023 Vol. 12 No. 13 Article 2200816
Designing stable quantum computers with the ability to correct errors responsibly requires a detailed understanding of the physical processes that underlie these devices. In this study, detailed quantum mechanical simulations of the atomic structure, charge distribution of electron density, and distribution and orientation of magnetic and quantum states as a function of applied external pressure ...
Added: October 11, 2026
Chibisov A., Gnidenko A., Chibisova M. et al., FlatChem 2023 Vol. 41 Article 100533
Manufacturing precise quantum computers with small errors in quantum operations, long coherence times, and low power consumption is the most important challenge in modern nanoelectronics. To understand the operating modes of such calculators in detail, both the optimal arrangement of the qubit system within the structure and changes in its magnetic properties must be comprehensively ...
Added: October 11, 2026
Khomitsky D.V., Bastrakova M. V., Pashin D. S., Physical Review B: Condensed Matter and Materials Physics 2025 Vol. 111 No. 08 Article 085427
Coupled spin evolution and tunneling together with the relaxation and decoherence effects are studied for the double quantum dot formed in a semiconductor nanowire and driven by the periodic electric field. Such structure represents a model of the spin and charge subsystems interacting via the strong spin-orbit coupling. It is found that at certain regimes ...
Added: September 6, 2026
Beck M. E., Seidov S., Mukhin S., Physical Review A: Atomic, Molecular, and Optical physics 2026 Vol. 113 No. 6 Article 063706
Quantum dissipation is studied in the superradiant phase of the extended Dicke model. It is demonstrated analytically by quantum mechanical derivation of the Lindblad equation for the Dicke model in the superradiant state coupled to Caldeira-Leggett thermal bath that the effective viscosity appearing in the semiclassical equations of motion of polaritonic condensate survives in the zero-temperature limit ...
Added: August 13, 2026
Dmitriev A. Y., Vasenin A. V., Gunin S. A. et al., Physical Review A: Atomic, Molecular, and Optical physics 2025 Vol. 111 No. 4 Article 043715
A cascade of two-level superconducting artificial atoms—a source and a probe—strongly coupled to a semi-infinite waveguide is a promising tool for observing nontrivial phenomena in quantum nonlinear optics. The probe atom can scatter an antibunched radiation emitted from the source, thereby generating a field with specific properties. We experimentally demonstrate wave mixing between nonclassical light ...
Added: June 21, 2025
A. A. Lyublinskaya, Nosov P. A., Burmistrov I. S., Physical Review B: Condensed Matter and Materials Physics 2025 Vol. 111 No. 9 Article 094302
Correlated quantum many-body states can be created and controlled by the dissipative protocols. Among these, particle number-conserving protocols are particularly appealing due to their ability to stabilize topologically nontrivial phases. Is there any fundamental limitation to their performance? We address this question by examining a general class of models involving a two-band fermion system subjected ...
Added: March 12, 2025
Венедиктов И. О., Kovalyuk V., Ан П. П. et al., Журнал технической физики 2024 Т. 94 № 7 С. 1158–1165
This work presents a superconducting single-photon detector with photon number resolution based on integrated optics on a silicon nitride platform for a wavelength of 914 nm. The detector is based on a space-time multiplexing scheme and consists of a plurality of pixel detectors connected in series by a microstrip line, which acts as a delay ...
Added: September 6, 2024
Asriyan N. A., Elistratov A. A., Yu. E. Lozovik, QUANTUM 2023 Vol. 7 Article 1144
Bose-condensation in a system of 2D quasiparticles is considered in the scope of a microscopic model. Mean-field dynamical equations are derived with the help of the Schwinger-Keldysh formalism and a simple model is proposed which allows to describe key features of condensate formation in systems with various quasiparticle decay rates. By analysing stationary solutions of ...
Added: April 16, 2024
M. Dryazgov, Biriukov Y., Dyakonov I. et al., Optica Quantum 2023 Vol. 1 No. 1 P. 14–18
We report a design and implementation of a resource-efficient spatial demultiplexer which produces four indistinguishable photons with efficiency of 39.7% per channel. Our scheme is based on a free-space storage/delay line which accumulates four photons and releases them by a controlled polarization rotation using a single Pockels cell. ...
Added: October 30, 2023
Sergeev T., Zyablovsky A., Andrianov E. et al., QUANTUM 2023 Vol. 7 Article 982
Exceptional point (EP) is a spectral singularity in non-Hermitian systems. The passing over the EP leads to a phase transition, which endows the system with unconventional features that find a wide range of applications. However, the need of using the dissipation and amplification limits the possible applications of systems with the EP. In this work, ...
Added: August 22, 2023
Sergeev T. T., Zyablovsky A. A., Andrianov E. S. et al., Journal of the Optical Society of America B: Optical Physics 2023 Vol. 40 No. 11 P. 2743–2750
An ultra-strong coupling regime takes place in a compound system when a coupling strength between the subsystems exceeds one tenth of the system eigenfrequency. It transforms into a deep-strong coupling regime when the coupling strength exceeds the system eigenfrequency. In these regimes, there are difficulties with description of relaxation processes without explicit considering of environment ...
Added: August 22, 2023
Alliluev A., Makarov D., Asriyan N. et al., Physics Letters A 2022 Vol. 453 Article 128492
Dynamics of exciton-polaritonic Bose-Einstein condensate is considered. We construct the stochastic Gross-Pitaevskii equation, where condensate is coupled to the excitonic reservoir in the non-Markovian regime. This equation is utilized for study of condensate formation. It is found that increasing of temperature results in transition from spatially uniform to fragmented pattern with onset of numerous vortices. ...
Added: October 24, 2022
Vladimirova Yulia, Zadkov V., Physics-Uspekhi 2022 Vol. 65 No. 3 P. 245–269
This review is devoted to studies of quantum optics effects for quantum emitters (QEs) in the near field of nanoparticles (NPs). In the simple model of a two-level QE located near a plasmon NP, we analyze the mechanisms for modifying the radiative and nonradiative decay rates and discuss the distribution of the near-field intensity and ...
Added: October 17, 2022
Yulia V. Vladimirova, Victor N. Zadkov, Nanomaterials 2021 Vol. 11 No. 8 Article 1919
This review is devoted to the study of effects of quantum optics in nanostructures. The mechanisms by which the rates of radiative and nonradiative decay are modified are considered in the model of a two-level quantum emitter (QE) near a plasmonic nanoparticle (NP). The distributions of the intensity and polarization of the near field around ...
Added: October 17, 2022
Cygorek M., Cosacchi M., Vagov A. et al., Nature Physics 2022 Vol. 18 No. 6 P. 662–668
Studies of the dynamics of open quantum systems are limited by the large Hilbert space of typical environments, which is too large to be treated exactly. In some cases, approximate descriptions of the system are possible, for example, when the environment has a short memory time or only interacts weakly with the system. Accurate numerical ...
Added: May 21, 2022
Cosacchi M., Seidelmann T., Mielnik-Pyszczorski A. et al., Advanced Quantum Technologies 2022 Vol. 2 No. 100131 Article 2100131
Light trapping is a crucial mechanism for synchronization in optical communication. Especially on the level of single photons, control of the exact emission time is desirable. In this paper, a single-photon buffering device composed of a quantum dot doped with a single Mn atom in a cavity is theoretically proposed. A method to detain a ...
Added: February 22, 2022
Bracht T., Cosacchi M., Seidelmann T. et al., PRX Quantum 2021 Vol. 2 Article 040354
The controlled preparation of the excited state in a quantum emitter is a prerequisite for its usage as a single-photon source—a key building block for quantum technologies. In this paper, we propose a coherent excitation scheme using off-resonant pulses. In the usual Rabi scheme, these pulses would not lead to a significant occupation. This is ...
Added: February 22, 2022
Sergeev T. T., Zyablovsky A. A., Andrianov E. S. et al., Scientific Reports 2021 Vol. 11 Article 24054
We demonstrate a new type of non-Hermitian phase transition in open systems far from thermal equilibrium, which can have place in the absence of an exceptional point. This transition takes place in coupled systems interacting with reservoirs at different temperatures. We show that the spectrum of energy flow through the system caused by the temperature ...
Added: January 2, 2022