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Graphene two terminal detector as THz mixer
Journal of Physics: Conference Series. 2021. Vol. 2086. No. 1. Article 012054.
The growing requirements for mobile communication networks (data transfer rates over 100 Gbps) makes it necessary to use carrier signal with a frequency of at least 100 GHz. This requires the development of cheap and broadband sub-terahertz (sub-THz) detectors. Here we report on our recent efforts toward the development of a heterodyne sub-THz detector based on a single layer graphene two-terminal device integrated with a bowtie antenna on a sapphire substrate. Our detector operates at frequency of 140 GHz, which corresponds to the maximum transmission of THz radiation in the Earth's atmosphere. The heterodyne detection is achieved by quasi-optical coupling of signals from two sub-THz radiation sources to the same detector. The measured frequency bandwidth is 5.8 GHz.
Копьев А., JETP Letters 2026 Vol. 123 No. 5 P. 310–316
The incompressible three-dimensional Euler equations develop very thin pancake-like regions of exponen tially increasing vorticity. The characteristic thickness of such regions decreases exponentially with time, while the other two dimensions do not change considerably, making the flow near each pancake strongly anisotropic. The pancakes emerge in increasing number with time, which may enhance the anisotropy ...
Added: September 18, 2026
Захаров А. В., Düven H., Capar M. I., Physics Letters A 2026 No. 576 Article 131388
Molecular dynamics simulations were carried out to study the structural properties of nematic pentyl
cyanobiphenyl (5CB) and pentyloxy cyanobiphenyl (5OCB) liquid crystals (LCs) doped with gold nanoparti
cles (GNPs) of different numbers, shapes and sizes. The spherical GNPs of two different radii and rod-like have
been doped in 5CB and 5OCB cyanobiphenyl liquid crystals. In order to describe ...
Added: September 17, 2026
Andreev D. V., Kornev S. A., Bondarenko G.G. et al., Inorganic Materials: Applied Research 2026 Vol. 17 No. 5 P. 1226–1230
Comparative studies are carried out to investigate high-field charge degradation effects in the gate
dielectric of metal—insulator—semiconductor (MIS) structures with aluminum and polysilicon gates.
Charging phenomena in MIS structures are explored using high-field electron injection into the dielectric
under conditions of gradually increasing voltage current density, with periodic short-term switching to a measurement
mode at a constant low injection ...
Added: September 15, 2026
Poddiakov A., / Series Social Science Research Network "Social Science Research Network". 2026. No. 7437658.
Clarity of knowledge and reasoning is necessary in many cases. Yet vagueness in scientific thinking related to surprise, curiosity, "ability to engage with not-knowing" (de Freitas) and abductive reasoning is also a crucially important source of scientific creativity which supplements combinatorial logic when dealing with the already known. Starting from studies by C. S. Peirce ...
Added: September 15, 2026
Water confined in heterogeneous clay–quartz pores: Structure and dynamics from atomistic simulations
Glushak A., Tararushkin E., Smirnov G., Colloids and Surfaces A: Physicochemical and Engineering Aspects 2027 Vol. 752 Article 141756
The molecular-scale behavior of water in heterogeneous clay–quartz systems is critical for understanding cementation processes in natural soils and compacted bentonite, which is crucial for oil recovery and nuclear waste disposal barriers construction. Here we investigate how heterogeneity of mixed Na-montmorillonite and α-quartz surfaces affect water structure and dynamics in nanopores of 2.5 to 60 Å ...
Added: September 15, 2026
Bochkin G., Doronin S., Fel’dman E. et al., Lobachevskii Journal of Mathematics 2024 Vol. 45 No. 3 P. 1188–1207
We consider the remote state restoring and perfect transfer of the zero-order coherence matrix (PTZ) in a spin system governed by the XXZ-Hamiltonian conserving the excitation number. The restoring tool is represented by several nonzero Larmor frequencies in the Hamiltonian. To simplify the analysis we use two approximating models including either step-wise or pulse-type time-dependence ...
Added: September 14, 2026
Fel’dman E. B., Lazarev I., Pechen A. N. et al., Quantum Information Processing 2026 Vol. 25 Article 121
We consider the state-restoring protocol based on the controlled interaction of a linear chain with environment through incoherent control by the specially adjusted step-wise time-dependent Lindblad operators. We show that the best restoring result (maximal scale factors in the restored state) corresponds to the symmetrical Lindblad equation. (0, 1)-excitation dynamics is considered numerically, and restoring ...
Added: September 14, 2026
Li S., Hu J., Lazarev I. 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., Lazarev I., 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
Борщевский А. Я., Physical Chemistry Chemical Physics 2025 Vol. 27 No. 9 P. 4793–4803
Through the consistent application of quantum statistical thermodynamics, functions of isothermal mixing of real rarefied gases and quantum gases in states of varying degrees of degeneracy are obtained. The reasons for the emergence and resolution of the “Gibbs paradox” and other “paradoxes” are analyzed. Numerical calculations of entropy and pressure jumps were performed using the ...
Added: September 14, 2026
D.L. Gurina, 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
P. M. Marychev, A. A. Shanenko, 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
Elesin L., Shilov A., Jana S. et al., Advanced Functional Materials 2026 P. 1–10
Thermoelectric materials, long explored for energy harvesting and thermal sensing, convert heat directly into electrical signals. Extending their application to the terahertz (THz) frequency range opens opportunities for low-noise, bias-free THz detection, yet conventional thermoelectrics lack the sensitivity required for practical devices. Thermoelectric coefficients can be strongly enhanced near van Hove singularities (VHS), though these ...
Added: May 28, 2026
Ивашенцева И. В., Федотов П. В., Каурова Н. С. et al., Журнал технической физики 2024 Т. 94 № 8 С. 1391–1397
A technology for sensitizing a structure consisting of a graphene nanoribbon (GNR) on a Si/GNR silicon substrate in the near-IR range of the electromagnetic spectrum is presented. This technology is based on doping the GNR with He4. A more than 25-fold increase in the response at a wavelength of 1.35 μm in the Si/GNR/He4 structure, ...
Added: December 23, 2025
Mehrabi-Kalajahi S., Ostovari Moghaddam A., Akbarpour S. et al., ACS Applied Energy Materials 2025 Vol. 8 No. 12 P. 8524–8531
High-entropy materials provide an interesting route for developing highly active electrocatalysts owing to their tunability and numerous active sites; however, their performance can be further improved with interfacial engineering in nanocomposite catalysts. In this study, (CoFeMnCuNiCr)3O4 high-entropy oxide (HEO) nanoparticles were synthesized and grafted onto graphene (HEO–G), graphene oxide (HEO–GO), and reduced graphene oxide (HEO–rGO) supports. ...
Added: June 16, 2025
A. N. Lyubchak, K. V. Shein, G.N. Goltsman et al., St. Petersburg Polytechnical University Journal: Physics and Mathematics 2024 Vol. 17 No. 3.2 P. 116–120
Terahertz (THz) integrated circuits is a promising platform to create low cost and efficient components for high-speed sixth-generation (6G) communication networks. One of the key components for this application is detectors and mixers integrated on THz silicon waveguide. Graphene, due to its unique and tunable properties such as zero band gap, high charge mobility and low electronic heat capacity, has ...
Added: November 5, 2024
Bondareva P., Shein K., Lyubchak A. N. et al., St. Petersburg Polytechnical University Journal: Physics and Mathematics 2024 Vol. 17 No. 3.2 P. 46–51
Graphene, due to its record low electron heat capacity and weak electron-phonon coupling at low temperatures, is considered as a promising material for creating terahertz hot electron bolometers. The main challenge to the development of such devices is the weak dependence of graphene resistance on temperature. Here we demonstrate measurement system based on Johnson noise ...
Added: November 5, 2024
Kravtsov M., Shilov A. L., Yang Y. et al., Nature Nanotechnology 2025 Vol. 20 No. 1 P. 51–56
Light incident upon materials can induce changes in their electrical conductivity, a phenomenon referred to as photoresistance. In semiconductors, the photoresistance is negative, as light-induced promotion of electrons across the bandgap enhances the number of charge carriers participating in transport. In superconductors and normal metals, the photoresistance is positive because of the destruction of the ...
Added: October 9, 2024