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First-order phase transition between superconducting and charge/spin density wave states causes their coexistence in organic metals
Physical Review B: Condensed Matter and Materials Physics. 2023. Vol. 108. No. 12.
Seidov S., Kochev V., Grigoriev P.
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
Dikhtievskaya K., Argunov E., Alexey I. Kartsev et al., The Journal of Physical Chemistry Letters 2026 Vol. 17 No. 17 P. 4999–5004
In this study we revealed the effect of scandium doping on the electronic and superconducting properties of the MgB2 compound. Calculations demonstrate that Sc substitutes for Mg atoms, acting as an electron donor. Mg substitution diminishes the density of states in the σ-band and attenuates the electron–phonon coupling, thereby elucidating the reduction in critical temperature. Simultaneously, ...
Added: June 2, 2026
S. A. Andreeva, Dzhikirba K. R., Shibalov M. V. et al., Physical Review B: Condensed Matter and Materials Physics 2026 Vol. 113 No. 10 Article L100503
In present work we report the first observations of two-dimensional plasma resonance with linear dispersion in superconducting NbN films fabricated by atomic layer deposition on sapphire and high-resistive (HR) silicon substrates. We have detected several consecutive resonance dips in THz transmission of the sample processed into the disc geometry. Increasing temperature results both in the ...
Added: March 12, 2026
Lukmanova R.M., Cohn I.A., Minakova V. E. et al., Physical Review B: Condensed Matter and Materials Physics 2025 Vol. 111 No. 22 Article 224510
The magnetoresistance of superconductor–topological insulator–superconductor structures, with indium as the superconductor and TaSe3 as the topological insulator, shows steplike features on the resistance under magnetic fields. These resistance steps result from the suppression of superconductivity, induced by the superconducting proximity effect in both the bulk and surface states of the topological insulator. The position and ...
Added: March 11, 2026
Ya. I. Rodionov, Rozhkov A. V., Beck M. E. et al., Physical Review B: Condensed Matter and Materials Physics 2025 Vol. 112 No. 20 P. –
We theoretically investigate a model with electrons and holes whose Fermi surfaces are perfectly nested. The fermions are assumed to be interacting, both with each other and with the lattice. To suppress inhomogeneous states, a sufficiently strong long-range Coulomb repulsion is included into the model. Using the mean field approximation, one can demonstrate that, in ...
Added: February 18, 2026
Vyacheslav D. Neverov, Karabassov T., Andrey V. Krasavin et al., Research 2026 Vol. 9 Article 1087
Majorana zero modes (MZMs) localized in vortex cores of topological superconductors are widely regarded promising building blocks for fault-tolerant quantum computation. However, their unambiguous detection is hindered by the extremely small energy spacing separating them from conventional Caroli-de Gennes-Matricon states. Using a microscopic Bogoliubov-de Gennes approach, we demonstrate that nonmagnetic impurities, rather than suppressing, can ...
Added: February 17, 2026
Kononova N., В кн.: XII Международная молодежная научная школа-конференция «Современные проблемы физики и технологий».: НИЯУ МИФИ, 2025. С. 167–169.
В работе исследованы термодинамические характеристики сверхпроводящего конденсата (вихревой материи), характерной для однозонных сверхпроводников в режиме перехода из первого рода во второй. На основе анализа изменения зависимости энергии Гиббса системы вихрей от внешнего магнитного поля сделаны выводы о характерных типах зависимости F(B) для такого перехода. Результаты демонстрируют, что для однозонных сверхпроводников в режиме межтиповой сверхпроводимости наблюдается ...
Added: February 2, 2026
Semenok D., Zhou D., Chen W. et al., Annalen der Physik 2025 Vol. 538 No. 1 Article e00467
We review five years of experimental and theoretical attempts (2020–2025) to enhance the superconducting critical temperature (Tc) of hydrogen-rich compounds by alloying binary superhydrides with additional elements. Despite predictions of higher Tc in ternary systems such as La–Y–H, La–Ce–H, and Ca–Mg–H, experiments consistently show that the maximum Tc in disordered ternary superhydrides does not exceed that of the ...
Added: January 24, 2026
Vyacheslav D. Neverov, Kalashnikov A., Andrey V. Krasavin et al., Beilstein Journal of Nanotechnology 2026 Vol. 17 P. 57–62
We present a comprehensive microscopic study of the intermediate mixed state in superconductors of the intertype (IT) regime separating types I and II. Using fully self-consistent Bogoliubov–de Gennes calculations for a lattice model, we analyze few-vortex configurations across the entire temperature range 0 < T < Tc. Our results demonstrate the key features of IT superconductivity, ...
Added: January 8, 2026
Tomayeva M., Vyacheslav D. Neverov, Andrey V. Krasavin et al., Beilstein Journal of Nanotechnology 2025 Vol. 16 P. 2265–2273
In the ballistic regime at finite temperatures, the proximity effect diminishes following an exponential pattern; however, at low or zero temperatures, this transition alters to a decay characterized by a power law with a dimensionality-dependent exponent. Here, we extend the current understanding of the proximity effect by exploring the role of normal metal–superconductor (NS) junction ...
Added: January 8, 2026
Ивашенцева И. В., Каурова Н. С., Воронов Б. М. et al., St. Petersburg Polytechnical University Journal: Physics and Mathematics 2025 Vol. 18 No. 3.2 P. 129–133
This paper focuses on the study of reactive magnetron sputtering thin NbN films for sensitization of hot electron bolometers. HEB will be utilized in the Millimetron space observatory. The main principle of operation is a superconductivity that is experimentally observed when NbN film is cooled to the temperature of a liquid helium. At a critical ...
Added: December 24, 2025
Khudchenko A., Turygin S., Golubev E. et al., Proceedings of SPIE 2025 Vol. 13102 P. 858–862
The Millimetron Space Observatory will be equipped with the cryogenically cooled instrument for a Space-Earth Very Large Baseline Interferometry (S-E VLBI). It will be a multi-channel heterodyne receiver with 7mm, 3mm, 1.3mm and 0.8mm channels. The VLBI instrument will have a multi-frequency capability, provided by signal splitting in the input optics and by back-end functionalities. ...
Added: December 23, 2025
Третьяков И. В., Худченко А. В., Рудаков К. И. et al., IEEE Transactions on Terahertz Science and Technology 2024 Vol. 15 No. 2 P. 191–199
The study of the origin and transport of water in the universe is an important part of the scientific program of the Millimetron space observatory. This will be made possible by observations conducted in single-dish mode using an onboard instrument—the high-resolution spectrometer (HRS). This instrument incorporates heterodyne array receivers operating within the range $0.5 -2.7$ ...
Added: December 23, 2025
Karabassov T., Bobkova I. V., Pavel M. Marychev et al., Beilstein Journal of Nanotechnology 2025 Vol. 17 P. 15–23
The diode effect in superconducting materials has been actively investigated in recent years. Plenty of different devices have been proposed as a platform to observe the superconducting diode effect. In this work, we discuss the possibility of a highly efficient superconducting diode design with controllable polarity. We propose a mesoscopic device that consists of two ...
Added: December 22, 2025
Kamashev A. A., Garif’yanov N. N., Validov A. A. et al., Physical Review B: Condensed Matter and Materials Physics 2025 Vol. 112 No. 13 Article 134509
The structures of the superconducting spin valve (SSV) Fe/Si3N4/Pb/Si3N4/Fe (where Si3N4 is a dielectric
insulating layer of controlled thickness) were investigated. The dependence of the magnitude of the SSV effect
on the thicknesses of the superconducting (S) and insulating (I) layers was studied. Optimization of the S and I
layer thicknesses enabled a complete switching between the normal ...
Added: December 20, 2025
Semenov A. G., Latyshev A., Andrei D. Zaikin, Physical Review B: Condensed Matter and Materials Physics 2025 Vol. 112 No. 14 Article 144501
We investigate the effects of fluxon cotunneling and quantum Coulomb drag in a system of two small
Josephson junctions coupled by means of mutual capacitanceCm. Depending on the value ofCm we identify three
different regimes of strong, intermediate, and weak coupling. Focusing our attention on the last two regimes we
develop a perturbation theory in the interaction and ...
Added: November 14, 2025
M. V. Parfenov, I. S. Burmistrov, Physical Review B: Condensed Matter and Materials Physics 2025 Vol. 112 No. 16 Article L161407
The spin and integer quantum Hall effects are two cousins of topological phase transitions in two-dimensional electronic systems. Their close relationship makes it possible to convert spin to integer quantum Hall effect by continuous increase in a symmetry breaking Zeeman magnetic field. We study microscopic and mesoscopic peculiarities of bulk-edge correspondence and a fate of ...
Added: November 9, 2025
Банников М. И., Селиванов Ю. Г., Мартовицкий В. П. et al., Письма в Журнал экспериментальной и теоретической физики 2025 Т. 122 № 4 С. 220–226
This work studies iron doping in the classical nematic superconductor SrxBi2Se3. Superconductivity is shown to be suppressed for an atomic fraction of Fe about 0.2%. At lower iron concentrations, the superconducting critical temperature and nematic superconductivity anisotropy remain unchanged. Magnetization measurements confirm Fe-induced paramagnetism. The crystal structure (lattice parameter c) and transport properties evolve smoothly ...
Added: November 9, 2025
Kalashnikov D., Seleznev G., Kudriashov A. et al., Physical Review B: Condensed Matter and Materials Physics 2025 Vol. 112 No. 14 Article 144504
We investigate the Josephson diode effect in an asymmetric SQUID consisting of a sinusoidal Josephson
junction formed by a Bi 2 Te 2 Se flake and a superconducting Nb nanobridge with a linear and multivalued current-phase relation (CPR). Current-voltage characteristics were measured both in the absence (dc regime) and presence (ac regime) of external microwave irradiation. ...
Added: November 9, 2025