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Magnetic disorder in superconductors: Enhancement by mesoscopic fluctuations
Physical Review B. 2018. Т. 97. № 014515. С. 1–13.
Burmistrov I.S., Skvortsov M. A.
We study the density of states (DOS) and the transition temperature Tc in a dirty superconducting film with rare classical magnetic impurities of an arbitrary strength described by the Poissonian statistics. We take into account that the potential disorder is a source of mesoscopic fluctuations of the local DOS, and, consequently, of the effective strength of magnetic impurities. We find that these mesoscopic fluctuations result in a nonzero DOS for all energies in the region of the phase diagram where without this effect the DOS is zero within the standard mean-field theory. This mechanism can be more efficient in filling the mean-field superconducting gap than rare fluctuations of the potential disorder (instantons). Depending on the magnetic impurity strength, the suppression of Tc by spin-flip scattering can be faster or slower than in the standard mean-field theory.
Publication based on the results of:
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We report on a comparative study of the optical and structural properties of short-period superlattices (SPSLs) based on digital ternary InGaAs/InAlAs alloys and their counterparts with quaternary InGaAlAs barriers, both grown on InP substrates and emitting in the 1.3 μm wavelength range. The heterostructures were grown by molecular beam epitaxy and analyzed using photoluminescence spectroscopy ...
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Babichev A., Bobrov M., Vasil'ev A. et al., Applied Physics Letters 2026 Vol. 128 Article 241102
High-quality planar cavities with low-absorption mirrors based on Al0.2Ga0.8As/Al0.9Ga0.1As layers demonstrate continuous wave lasing at a wavelength of 956 nm. At 300 K, the threshold power density and the quality-factor at the threshold are 4.2 kW/cm2 and 6800. Increasing the pump level above two thresholds results in an enlargement in the quality-factor to at least 19 ...
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Pilé I., Shchur L., Deng Y., Physical Review B: Condensed Matter and Materials Physics 2026 Vol. 114 Article 014101
We investigate the spatial overlap of successive spin configurations in Markov chain Monte Carlo simulations using the local Metropolis algorithm and the Swendsen-Wang and Wolff cluster algorithms. We examine the dynamics of these algorithms for models in different universality classes: Ising model, Potts model with three components, and four-state Potts model. The overlap of two ...
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МФТИ, 2025.
абота редакции научного журнала «Труды Московского физико-технического института» (кратко «Труды МФТИ»), редакционной коллегии и редакционного совета осуществляется в соответствии с Положением, утвержденным ректором института. В состав редакционной коллегии входят руководители института, факультетов, институтских и факультетских кафедр. Главный редактор журнала —президент МФТИ, член-корр. РАН Кудрявцев Н.Н.
Журнал «Труды МФТИ» входит в базу данных РИНЦ (Российский Индекс Научного Цитирования) и доступен в электронной ...
Added: July 4, 2026
Bobkov G. A., Bobkov G. A., Bobkova I. V. et al., Journal of Superconductivity and Novel Magnetism 2025 Vol. 38 Article 239
In recent years, a number of studies have predicted the emergence of a nontrivial proximity effect in superconductor/antiferromagnet (S/AF) heterostructures. This effect is of considerable interest for the efficient integration of antiferromagnetic materials into the fields of superconducting spintronics and electronics. A key element of this proximity effect is the Néel triplet correlations, initially predicted ...
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The miniaturization of superconducting electronics demands precise control over quasiparticle dynamics at the nanoscale. Understanding and controlling quasiparticle dynamics is essential for advancing superconducting electronics, particularly as device dimensions approach the nanoscale. Here we present direct experimental evidence for the quasiparticle-to-supercurrent conversion in planar SN-N-NS Josephson nanobridges with submicron electrodes. By employing a versatile measurement ...
Added: July 2, 2026
Polevoy K. B., Bakurskiy S. V., Ruzhickiy V. I. et al., Physical Review Applied 2026 Vol. 25 P. 024030-1–024030-12
We present a comprehensive study of planar Nb-Al-Nb Josephson junctions with submicrometer dimen sions (L ≈ 100 nm, active area of approximately 5 × 104 nm2), where the intrinsic superconductivity of the aluminum weak link plays a crucial role in enhancing device performance. Through a combi nation of theoretical modeling and experimental characterization, we demonstrate ...
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Никонов В. Д., Никитин С. С., Патракеев М. В., Ionics 2025 Vol. 31 No. 1 P. 675–687
Modification of perovskite-type oxides is an effective way to develop functional materials with advanced properties. The effects of cerium introduction into the A sublattice of La0.5Sr0.5FeO3−δ and variation of La:Sr ratio on the defect structure and charge transfer characteristics were studied in this work. The LaxSr0.85−xCe0.15FeO3−δ oxides were found to be single-phase with cubic (x = 0.1) and orthorhombic ...
Added: June 26, 2026
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‒
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Абрамов-Максимов В. Е., И.А. Бакунина, Геомагнетизм и аэрономия 2026 Т. 66 № 3 С. 515–529
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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 ...
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Сформулирована модель тлеющего газового разряда в смеси аргона и паров ртути при наличии
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аргона (реакция Пеннинга). Показано, что в случае катода без диэлектрической пленки при
повышении температуры до ...
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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
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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 ...
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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′ ...
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Babkin S. S., Lyublinskaya A. A., I. S. Burmistrov, Physical Review Research 2022 Vol. 4 No. 2 Article 023202
The interplay of a potential and magnetic disorder in superconductors has remained an active field of research for decades. Within the framework of the Usadel equation, we study the local density of states (LDOS) near a solitary classical magnetic impurity in a dirty superconducting film. We find that a potential disorder results in broadening of ...
Added: November 13, 2022
K. Yu. Arutyunov, Lehtinen J. S., Radkevich A. A. et al., Physics of the Solid State 2017 Vol. 59 No. 11 P. 2110–2113
The current–voltage characteristics of superconductor–insulator–semiconductor (S1–I–S2)
tunnel junctions, where superconducting electrode S2 is a thin nanowire, are studied experimentally. The
observed blurring of the gap singularities is interpreted as a manifestation of the order parameter quantum
fluctuations. We propose a model taking into account the broadening of the density of states due to the interaction
of electrons with the ...
Added: November 29, 2017
Arutyunov K., Lehtinen J. S., Superconductor Science and Technology 2013 Vol. 26 No. 3 P. 039503–039503
On the second page, after equation (1), the statement
‘. . . where RN is the normal state resistance, RQ D h=2e D
6:45 k is the superconducting quantum resistance, . . . ’
contains a misprint. The correct expression is RQ D h=.2e/2 D
6:45 k. ...
Added: March 24, 2014
Arutyunov K., Lehtinen J. S., Superconductor Science and Technology 2012 Vol. 25 P. 1240071–1240075
In a number of recent experiments it has been demonstrated that in ultra-narrow
superconducting channels quantum fluctuations of the order parameter, alternatively called
quantum phase slips, are responsible for the finite resistance well below the critical
temperature. Acceptable agreement between those experiments and the models describing
quantum fluctuations in quasi-one-dimensional superconductors has been established.
However, the very concept of phase ...
Added: March 24, 2014
Arutyunov K., Sajavaara T., Lehtinen J. S. et al., Physical Review B: Condensed Matter and Materials Physics 2012 Vol. 85 No. 9 P. 0945081–0945087
Electron transport properties of titanium nanowires were experimentally studied. Below the effective diameter
50nm all samples demonstrated a pronounced broadening of the R(T ) dependencies, which cannot be accounted
for by thermal fluctuations. Extensive microscopic and elemental analyses indicate the absence of structural or/and
geometrical imperfections capable of broadening the R(T ) transition to such an extent. We ...
Added: March 24, 2014
Arutyunov K., Lehtinen J. S., Zakharov K., Physical Review Letters 2012 Vol. 109 No. 18 P. 187001–187005
Quantum fluctuations in quasi-one-dimensional superconducting channels leading to spontaneous
changes of the phase of the order parameter by 2, alternatively called quantum phase slips (QPS),
manifest themselves as the finite resistance well below the critical temperature of thin superconducting
nanowires and the suppression of persistent currents in tiny superconducting nanorings. Here we report the
experimental evidence that in a ...
Added: March 24, 2014