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Fluctuations and photon statistics in a quantum metamaterial near a superradiant transition
Physical Review A: Atomic, Molecular, and Optical physics. 2019. Vol. 99. No. 6. P. 063821.
Dmitriy S. Shapiro, Lozovik Y., Погосов В. В., Ремизов С. В., Рубцов А. Н.
The analysis of single-mode photon fluctuations and their counting statistics at the superradiant phase transition is presented. The study concerns the equilibrium Dicke model in a regime where the Rabi frequency, related to a coupling of the photon mode with a finite-number qubit environment, plays the role of the transition's control parameter. We use the effective Matsubara action formalism based on the representation of Pauli operators as bilinear forms with complex and Majorana fermions. Then, we address fluctuations of superradiant order parameter and quasiparticles. The average photon number, the fluctuational Ginzburg-Levanyuk region of the phase transition, and Fano factor are evaluated. We determine the cumulant-generating function which describes a full counting statistics of equilibrium photon number. Exact numerical simulation of the superradiant transition demonstrates quantitative agreement with analytical calculations.
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
Timoshuk I., Makhlin Y., Journal of Low Temperature Physics 2024 Vol. 217 P. 167–186
Superconducting heterostructures can host subgap states known as Andreev bound states. In topological superconducting systems, novel zero-energy Andreev states were discovered known as Majorana zero modes. Local Majorana zero modes serve as basic ingredients of topological quantum computations. To simplify manipulations, one can use chiral Majorana-fermion edge transport in gapped two-dimensional systems. Here we demonstrate ...
Added: May 7, 2024
Ilya S., Grigoriy M., Moskalenko I. et al., Physical Review Applied 2024 Vol. 21 No. 4 P. 0
The Toffoli gate takes a special place in the quantum information theory. It opens up a path for efficient
implementation of complex quantum algorithms. Despite tremendous progress of the quantum processors
based on the superconducting qubits, realization of a high-fidelity three-qubit operation is still a challenging
problem. Here, we propose a way to perform a high-fidelity CCZ gate ...
Added: April 24, 2024
M. V. Parfenov, Kachorovskii V. Y., I. S. Burmistrov, Physical Review B: Condensed Matter and Materials Physics 2022 Vol. 106 No. 23 Article 235415
We develop a theory of anomalous elasticity in disordered two-dimensional flexible materials with orthorhombic crystal symmetry. Similar to the clean case, we predict the existence of infinitely many flat phases with anisotropic bending rigidity and Young's modulus showing power-law scaling with momentum controlled by a single universal exponent the very same as in the clean ...
Added: November 13, 2023
Yury A. Budkov, Petr E. Brandyshev, Nikolai N. Kalikin, Soft Matter 2023 Vol. 19 P. 3281–3289
Based on the random phase approximation, we develop a molecular theory of self-coacervation in zwitterionic polymer solutions. We show that the interplay between the volume interactions of the monomeric units and electrostatic correlations of charged groups on a polymer backbone can result in liquid-liquid phase separation (self-coacervation). We analyse the behavior of the coacervate phase ...
Added: April 18, 2023
Bastrakova M. V., Klenov N. V., A. M. Satanin, Journal of Experimental and Theoretical Physics 2020 Vol. 131 No. 4 P. 507–519
© 2020, Pleiades Publishing, Inc.Abstract: The conventional technique for controlling the states of individual qubits and quantum registers is based on the use of high-frequency modulated pulses whose carrier frequency is close to the transition frequency between the ground states of “artificial atoms” and “molecules” (the Rabi technique). In this paper, an alternative concept for ...
Added: October 26, 2022
Shapiro D. S., Pogosov W. V., Lozovik Y., Physical Review A: Atomic, Molecular, and Optical physics 2020 Vol. 102 No. 2 Article 023703
In view of recent proposals for the realization of anisotropic light-matter interaction in such platforms as (i) nonstationary or inductively and capacitively coupled superconducting qubits, (ii) atoms in crossed fields, and (iii) semiconductor heterostructures with spin-orbital interaction, the concept of a generalized Dicke model, where coupling strengths of rotating wave and counter-rotating wave terms are ...
Added: October 31, 2021
Min N., Kwon Y., Scientific Reports 2020 Vol. 10 No. 1 P. 8247-1–8247-35
Sequential state discrimination is a strategy for N separated receivers. As sequential state
discrimination can be applied to multiparty quantum key distribution (QKD), it has become one of
the relevant research fields in quantum information theory. Up to now, the analysis of sequential
state discrimination has been confined to special cases. In this report, we consider a generalization ...
Added: November 16, 2020
Min Namkung, Younghun K., Scientific Reports 2019 Vol. 9 No. 1 P. 19664-1–19664-19
Quantum state discrimination of coherent states has been one of important problems in quantum
information processing. Recently, R. Han et al. showed that minimum error discrimination of two
coherent states can be nearly done by using Jaynes-Cummings Hamiltonian. In this paper, based on the
result of R. Han et al., we propose the methods where minimum error discrimination ...
Added: November 16, 2020
Min Namkung, Younghun K., Scientific Reports 2018 Vol. 8 No. 1 P. 16915-1–16915-18
Sequential state discrimination is a strategy for quantum state discrimination of a sender’s quantum
states when N receivers are separately located. In this report, we propose optical designs that can
perform sequential state discrimination of two coherent states. For this purpose, we consider not
only binary phase-shifting-key (BPSK) signals but also general coherent states, with arbitrary prior
probabilities. Since ...
Added: November 16, 2020
Min Namkung, Younghun K., Scientific Reports 2018 Vol. 8 No. 1 P. 6515-1–6515-13
Recently, J. A. Bergou et al. proposed sequential state discrimination as a new quantum state
discrimination scheme. In the scheme, by the successful sequential discrimination of a qubit state,
receivers Bob and Charlie can share the information of the qubit prepared by a sender Alice. A merit
of the scheme is that a quantum channel is established between ...
Added: November 16, 2020
Min Namkung, Younghun K., Journal of Physics A: Mathematical and Theoretical 2018 Vol. 51 No. 45 P. 455302-1–455302-16
In this article we investigate the non-classical correlation in a macroscopic
physical system. As a tool, we consider an optical hybrid state that is a micro–
macro entangled state. Our strategy is to study the behavior of non-classical
correlation in an optical hybrid state that may go through noisy channels. We
study the violation of two inequalities, which are ...
Added: November 16, 2020
Min Namkung, Younghun K., Physical Review A: Atomic, Molecular, and Optical physics 2017 Vol. 96 No. 2 P. 022318-1–022318-8
Recently, sequential state discrimination, as a quantum-key distribution protocol, has been proposed for
multiple receivers. A previous study [J. A. Bergou et al., Phys. Rev. Lett. 111, 100501 (2013)] showed that
every receiver could successfully perform a sequential state discrimination of two pure states with identical
prior probabilities. In this study, we extend the sequential state discrimination to ...
Added: November 16, 2020
Min Namkung, Jinho C., Jaehee S. et al., International Journal of Theoretical Physics 2015 Vol. 54 No. 9 P. 3340–3349
In this article, we investigate the error bound of quantum discord, obtained from
the analytic formula of Ali et al. (Phys. Rev. A 81, 042105, 2010) for the case of general
X states and from the analytic formula of Fanchini et al. (Phys. Rev. A 81, 052107, 2010)
for the case of symmetric X states. For this purpose ...
Added: November 16, 2020
International Journal of Theoretical Physics 2015 Vol. 54 No. 9 P. 3340–3349
In this article, we investigate the error bound of quantum discord, obtained from
the analytic formula of Ali et al. (Phys. Rev. A 81, 042105, 2010) for the case of general
X states and from the analytic formula of Fanchini et al. (Phys. Rev. A 81, 052107, 2010)
for the case of symmetric X states. For this purpose ...
Added: November 16, 2020
Scientific Reports 2019 Vol. 9 No. 1 P. 19664-1–19664-19
Quantum state discrimination of coherent states has been one of important problems in quantum
information processing. Recently, R. Han et al. showed that minimum error discrimination of two
coherent states can be nearly done by using Jaynes-Cummings Hamiltonian. In this paper, based on the
result of R. Han et al., we propose the methods where minimum error discrimination ...
Added: November 3, 2020
Scientific Reports 2018 Vol. 8 No. 1 P. 16915-1–16915-18
Sequential state discrimination is a strategy for quantum state discrimination of a sender’s quantum
states when N receivers are separately located. In this report, we propose optical designs that can
perform sequential state discrimination of two coherent states. For this purpose, we consider not
only binary phase-shifting-key (BPSK) signals but also general coherent states, with arbitrary prior
probabilities. Since ...
Added: November 3, 2020