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Magnon-cooparons in magnet-superconductor hybrids
Communications Materials. 2022. Vol. 3. Article 95.
Bobkova I. V., Bobkov A. M., Kamra A., Belzig W.
Generation and detection of spinful Cooper pairs in conventional superconductors has been intensely pursued by designing increasingly complex magnet-superconductor hybrids. Here, we demonstrate theoretically that magnons with nonzero wavenumbers universally induce a cloud of spinful triplet Cooper pairs around them in an adjacent conventional superconductor. The resulting composite quasiparticle, termed magnon-cooparon, consists of a spin flip in the magnet screened by a cloud of the spinful superfluid condensate. Thus, it inherits a large effective mass, which can be measured experimentally. Furthermore, we demonstrate that two magnetic wires deposited on a superconductor serve as a controllable magnonic directional coupler mediated by the nonlocal and composite nature of magnon-cooparons. Our analysis predicts a quasiparticle that enables generation, control, and use of spinful triplet Cooper pairs in the simplest magnet-superconductor heterostructures.
Li S., Hu J., Лазарев И. Д. et al., Annals of Physics 2026 Vol. 494 Article 170618
The distribution of entanglement is a crucial task for quantum communication towards realizing a globe-spanning quantum internet. Recently, a protocol for deterministic long-distance distribution of macroscopic entanglement over a network of ensembles of qubits was introduced (Pyrkov et al., 2025). It was shown that this protocol allows for the propagation of macroscopic amounts of entanglement ...
Added: September 14, 2026
Pyrkov A., Лазарев И. Д., Byrnes T., Advanced Quantum Technologies 2025 Article 2400524
Distributing long-distance entanglement is a fundamental goal that is necessary for a variety of tasks such as quantum communication, distributed quantum computing, and quantum metrology. Currently quantum repeater schemes typically aim to distribute one ebit at a time, the equivalent of one Bell pair's worth of entanglement. Here, a scheme is presented to distribute a ...
Added: September 14, 2026
I. D. Lazarev, Narozniak M., Byrnes T. et al., Physical Review A: Atomic, Molecular, and Optical physics 2025 Vol. 111 No. 012416 Article 012416
Unsupervised machine learning is one of the main techniques employed in artificial intelligence. We introduce an algorithm for quantum-assisted unsupervised data clustering using the self-organizing feature map, a type of artificial neural network. The complexity of our algorithm scales as 𝑂(𝐿𝑁), in comparison to the classical case which scales as 𝑂(𝐿𝑀𝑁), where 𝑁 is the ...
Added: September 14, 2026
Gurina D., Fashchevsky K. A., Oparin R. D. et al., Surfaces and Interfaces 2026 Vol. 98 Article 110545
In this work, we combine experimental characterization and molecular dynamics (MD) simulations to elucidate the molecular mechanisms governing the impregnation of mefenamic acid (MFA) into nanocrystalline cellulose (NCC) aerogels. NCC aerogels were impregnated with MFA in scCO2, and low-temperature nitrogen adsorption revealed a concentration-dependent decrease in surface area, pore volume, and pore size, with an ...
Added: September 8, 2026
Huang D., Chen Y., Luo X. et al., Chinese Journal of Physics 2026 Vol. 103 P. 1803–1814
Using self-consistent Bogoliubov-de Gennes calculations for kagome flakes framed by armchair
and flat edges, we observe a configuration-dependent spatial inhomogeneity of an 𝑠-wave superconducting
condensate. Specifically, at half-filling, the local pair potential is significantly enhanced
by up to 77.8% at edge centers and up to 148.9% at corners, subsequently boosting their
local critical temperatures by up to 13.5% and ...
Added: September 7, 2026
Marychev P., Shanenko A., Physical Review B: Condensed Matter and Materials Physics 2026 Vol. 114 No. 7 Article 074509
We investigate the effect of weak interband impurity scattering on the intertype (IT) domain between type-I and type-II superconductivity in diffusive two-band superconductors. Our results show that the significant broadening of the IT domain with increasing band diffusivity ratio, previously established in the absence of interband scattering, persists under weak interband scattering. However, depending on ...
Added: September 7, 2026
Denis K., Н. Новгород: Нижегородский государственный университет им. Н.И. Лобачевского, 2025.
В учебном пособии излагаются элементы теории и описание избранных экспериментальных результатов, полученных в активно развивающейся физике топологических изоляторов. Рассмотрены наиболее простые модели поверхностных и краевых состояний в двумерных и трёхмерных топологических изоляторах, их структура в магнитном поле, а также основы топологических методов для определения их свойств. Обсуждаются модели квантовых точек, формируемых в топологических изоляторах. Приведены ...
Added: September 6, 2026
Denis K., Звонков Б. Н., Вихрова О. В. et al., Физика твердого тела 2021 Т. 63 № 9 С. 1245–1252
Сочетанием методов МОС-гидридной эпитаксии и импульсного лазерного нанесения изготовлены гетеронаноструктуры InGaAs/GaAs со слоем (Ga, Mn)As на поверхности, и исследовано влияние воздействия импульсного эксимерного лазера (длина волны 248 nm, длительность импульса ~30 ns, плотность энергии в диапазоне 200-360 mJ/cm2) на их излучательные, структурные и гальваномагнитные свойства. При исследованиях использовалась спектроскопия фотолюминесценции, дополненная возможностью анализа поляризационных характеристик ...
Added: September 6, 2026
Воздействие импульсов эксимерного лазера на светоизлучающие InGaAs/GaAs-структуры с (Ga, Mn)As-слоем
Denis K., Вихрова О. В., Данилов Ю. А. et al., Физика твердого тела 2021 Т. 63 № 3 С. 346–355
Исследована возможность модифицирования лазерным отжигом свойств слоя (Ga, Mn)As, расположенного на поверхности квантово-размерной InGaAs/GaAs-структуры, с сохранением ее излучательных свойств. Для проведения исследований сочетанием методов МОС-гидридной эпитаксии и импульсного лазерного нанесения были изготовлены структуры с четырьмя квантовыми ямами InGaAs/GaAs, (содержание индия от 0.08 до 0.25), расположенными на различном расстоянии от слоя (Ga, Mn)As. В процессе исследований ...
Added: September 6, 2026
Denis K., Lavrukhina E. A., Journal of Physics: Conference Series 2021 Vol. 2103 Article 012201
A model of quasistationary states is constructed for the one-dimensional edge states propagating along the edge of a two-dimensional topological insulator based on HgTe/CdTe quantum well in the presence of magnetic barriers with finite transparency. The lifetimes of these quasistationary states are found analytically and numerically via different approaches including the solution of the stationary ...
Added: September 6, 2026
Denis K., Dorokhin M. V., Ved M. V. et al., Physical Review B: Condensed Matter and Materials Physics 2021 Vol. 104 No. 12 Article 125309
The GaAs/InGaAs quantum wells with a ferromagnetic δ〈Mn〉 layer in GaAs barrier demonstrate a set of interesting spin-related phenomena originating from Mn-hole interaction. One of such phenomena is a spin-memory effect which consists of Mn spin polarization induced by interaction with vicinity spin-polarized holes generated under the exposure by short circularly polarized light pulses. Here long Mn ...
Added: September 6, 2026
Denis K., Запруднов Н. А., Физика и техника полупроводников 2022 Т. 56 № 10 С. 973–978
Исследована динамика туннелирования и спина для дырочных состояний в двойной квантовой точке на основе GaAs при наличии сильного спин-орбитального взаимодействия и периодического электрического поля. Рассмотрены режимы туннелирования с переворотом спина в условиях "медленной" эволюции, при которой частота поля меньше остальных энергетических параметров стационарной части гамильтониана. Обнаружено, что в таких условиях туннелирование с переворотом спина может ...
Added: September 6, 2026
Denis K., Kalentyeva I. L., Vikhrova O. V. et al., Journal of Magnetism and Magnetic Materials 2022 Vol. 556 Article 169360
We have investigated the layers of the (Ga,Mn)As diluted magnetic semiconductor with the thickness in the range of 150 – 400 nm, which have been formed by the combination of the methods of a pulsed laser deposition and a post-growth pulsed laser annealing. It has been found that the laser annealing has a significant effect on the structural, ...
Added: September 6, 2026
Denis K., Konakov A. A., Lavrukhina E. A., Journal of Physics: Condensed Matter 2022 Vol. 34 Article 405302
A model of bound state formation from the delocalized edge states of 2D topological insulator (TI) is derived by considering the effects of magnetic barriers attached to the edge of the HgTe/CdTe quantum well. The resulting structure has a spatial form of 1D quantum dot (QD) with variable number of bound states depending on barrier ...
Added: September 6, 2026
Мещеряков А. А., Сафин А. Р., Kalyabin D. et al., Радиотехника и электроника 2025 Т. 70 № 12 С. 1190–1199
Теоретически исследовано взаимодействие резонансных мод в обменно-связанной двухслойной структуре скошенный антиферромагнетик/ферромагнетик. Методом гамильтонова формализма получены выражения, описывающие зависимость резонансных частот колебаний намагниченности от внешнего постоянного магнитного поля. Исследовано влияние связи между ферро- и антиферромагнитным слоями на ширину щели гибридизации и на величину внешнего магнитного поля, при котором наблюдается гибридизация между резонансной модой в ферромагнетике и нижней резонансной модой в антиферромагнетике. Показано, ...
Added: February 5, 2026
Лекомцев Н. В., Pugach N., В кн.: Межвузовская научно-техническая конференция студентов, аспирантов и молодых специалистов имени Е.В. Арменского. Москва, 2024.: М.: ООО "Издательский дом Медиа паблишер", 2024. С. 216–218.
The study investigates the controllable proximity effect regulated by spin switching in a superconductor-helimagnet bilayer, comparing the calculated critical parameters of the structure with experimental data. The research is conducted as part of the development of a superconducting spin valve model ...
Added: December 7, 2024
Yaroslav V. Turkin, Nataliya Pugach, Beilstein Journal of Nanotechnology 2023 Vol. 14 P. 233–239
In this work we theoretically investigate the spin dynamics of superconducting condensate proximity coupled with the single FMR mode uniform periodical precessing magnetization. The theoretical model of the inverse proximity effect is built within quasicalssical formalism using time-dependent Usadel equations. Frequency representation of Usadel equations allows to turn non-stationary periodic problem to the stationary one. ...
Added: November 17, 2022
Turkin Y. V., Pugach N., Екомасов Е. Г. et al., Физика металлов и металловедение 2023 Т. 124 № 1 С. 42–48
This paper presents a theoretical study of the dynamics of the induced magnetization and spin current
arising in a layer of an dirty superconductor due to the proximity to a ferromagnetic dielectric with a
uniform periodically precessing magnetization. The dynamics of the observed physical quantities is described
within the semi-classical Usadel–Floquet formalism, which makes it possible to study ...
Added: November 17, 2022
Pugach N., Safonchik M. O., Belotelov V. et al., / Series "cond-mat". 2022. No. 2110.00369.
A detailed investigation of a superconducting spin-triplet valve is presented. This spin-valve consists of a superconducting film covering a metal with an intrinsic spiral magnetic order, which could result from competing isotropic exchanges or, if the crystal lattice breaks central symmetry, from asymmetric Dzyaloshinskii-Moriya exchange. Depending on the anisotropy, such a metal may change its ...
Added: November 16, 2022
Pugach N., Safonchik M. O., Belotelov V. et al., Physical Review Applied 2022 Vol. 18 No. 5 Article 054002
A detailed investigation of a superconducting spin-triplet valve is presented. This spin valve consists of a superconducting film covering a metal with an intrinsic spiral magnetic order, which could result from competing isotropic exchanges or, if the crystal lattice breaks central symmetry, from asymmetric Dzyaloshinskii-Moriya exchange. Depending on the anisotropy, such a metal may change ...
Added: November 2, 2022
Amundsen M., Bobkova I. V., Kamra A., Physical Review B: Condensed Matter and Materials Physics 2022 Vol. 106 No. 4 Article 144411
Nonlinear devices, such as transistors, enable contemporary computing technologies. We theoretically investigate nonlinear effects, bearing a high fundamental scientific and technical relevance, in magnonics with emphasis on superconductor-ferromagnet hybrids. Accounting for a finite magnon chemical potential, we theoretically demonstrate magnonic spin Joule heating, the spin analog of conventional electronic Joule heating. Besides suggesting a key ...
Added: October 28, 2022
Pugach N., Heim D., Seleznev D. V. et al., Superconductor Science and Technology 2022 Vol. 35 Article 025002
We propose a superconducting spin valve based on a Josephson junction with B20-family
magnetic metal as a barrier material. Our analysis shows that the states of this element can be
switched by reorienting the intrinsic non-collinear magnetization of the spiral magnet. This
reorientation modifies long-range spin-triplet correlations and thereby strongly influences the
critical Josephson current. Compared to superconducting spin ...
Added: March 26, 2022
НАМАГНИЧЕННОСТЬ В БИСЛОЯХ СВЕРХПРОВОДНИК–ФЕРРОМАГНИТНЫЙ МЕТАЛЛ, ВЫЗВАННАЯ ОБРАТНЫМ ЭФФЕКТОМ БЛИЗОСТИ
Yagovtsev V., Pugach N., Екомасов Е. Г. et al., Физика металлов и металловедение 2021 № 9 С. 908–916
Within the Green’s function formalism, the magnetization induced by the inverse proximity effect in bilayers containing a superconductor and a strongly spin-polarized ferromagnetic metal is studied. The Usadel equations written for the dirty superconductor model are solved with boundary conditions suitable for strongly spin-polarized ferromagnetic materials. The cases of near-critical temperatures and a weak proximity ...
Added: October 31, 2021
Beginin E. N., Kalyabin D., Popov P. A. et al., , in: Three-Dimensional Magnonics: Layered, Micro- and Nanostructures.: Singapore: Jenny Stanford Publishing, 2019. Ch. 3 P. 67–104.
Magnonics, a research field that uses spin waves, collective excitations of ordered magnetic materials, or magnons (their quanta) as a tool for signal processing, communication, and computation, has rapidly grown during the past decade because of the low-energy consumption and potential compatibility with next-generation circuits beyond CMOS electronics. The interest in 3D magnonic nanostructures follows the ...
Added: October 26, 2021