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Tiulina, V., Iomdina, E., Goltsman, G., Seliverstov, S., Sianosyan, A., Teplyakova, K., et al. (2019). UVB promotes the initiation of uveitic inflammatory and changes in thehydration of the cornea in vivo (Vol. 9).
Abstract: Recently, active research has been conducted in the field of terahertz (THz) scanning of human tissues for noninvasive determination of their hydration level, which haves hown high diagnostic efficiency of this technology in various pathological conditions. Recently, we have developed a laboratory model of the facility for monitoring the state of the water balance of the cornea using THz scanning in vivo, which opens up the possibility of applying this approach in ophthalmology. The aim of the work wasto compare the results of the THz scan of the cornea with its clinical changes using the example of an experimental model of the UV induced keratouveitis. Anexperimental study, which included a comprehensive assessment of clinical changes in the cornea of rabbits during keratouveitis induction, revealed a decrease in the stability of the tear film, pathological changes in the corneal epithelium and stroma, as well as its anatomical and optical parameters. Comparison of data obtained in the THz scan of the cornea with tears production, optical coherence tomography and confocal microscopy showed their consistency in all observation periods, which allows us to conclude that the developed laboratory setup works and the feasibility of further research to promote the corneal hydration evaluation technology in clinical practice. Acknowledgements: Research was funded by the RSF, grant number 161500255.
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Emelianov, A. V., Nekrasov, N. P., Moskotin, M. V., Fedorov, G. E., Otero, N., Romero, P. M., et al. (2021). Individual SWCNT transistor with photosensitive planar junction induced by two‐photon oxidation. Adv. Electron. Mater., 7(3), 2000872.
Abstract: The fabrication of planar junctions in carbon nanomaterials is a promising way to increase the optical sensitivity of optoelectronic nanometer-scale devices in photonic connections, sensors, and photovoltaics. Utilizing a unique lithography approach based on direct femtosecond laser processing, a fast and easy technique for modification of single-walled carbon nanotube (SWCNT) optoelectronic properties through localized two-photon oxidation is developed. It results in a novel approach of quasimetallic to semiconducting nanotube conversion so that metal/semiconductor planar junction is formed via local laser patterning. The fabricated planar junction in the field-effect transistors based on individual SWCNT drastically increases the photoresponse of such devices. The broadband photoresponsivity of the two-photon oxidized structures reaches the value of 2 × 107 A W−1 per single SWCNT at 1 V bias voltage. The SWCNT-based transistors with induced metal/semiconductor planar junction can be applied to detect extremely small light intensities with high spatial resolution in photovoltaics, integrated circuits, and telecommunication applications.
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Селиверстов, С. В., Финкель, М. И., Рябчун, С. А., Воронов, Б. М., Каурова, Н. С., Селезнев, В. А., et al. (2014). Терагерцевый сверхпроводниковый детектор с аттоджоулевым энергетическим разрешением и постоянной времени 25 пс. In Труды XVIII международного симпозиума «Нанофизика и наноэлектроника» (Vol. 1, pp. 91–92).
Abstract: Представлены результаты измерения энергетического разрешения терагерцевого сверхпроводникового NbN-детектора на эффектеэлектронного разогрева, работающего при температуре около 10 К. Использование инновационной in situ технологии производства привело к существенному улучшению чувствительности детектора. Увеличение быстродействия детектора было достигнуто за счет реализации дополнительного диффузионного канала охла-ждения электронной подсистемы. Измеренное значение эквивалентной мощности шума на частоте 2.5 ТГц составило 2.0×10-13Вт•Гц-0.5, постоянной времени 25 пс. Соответствующее расчетное значение энергетического разрешения составило 2.5 аДж.
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Бурмистрова, А. В., & Девятов, И. А. (2014). Расчет электронного транспорта в гетероструктурах, содержащих многозонные сверхпроводники. In Труды XVIII международного симпозиума «Нанофизика и наноэлектроника» (Vol. 1, pp. 21–22).
Abstract: В рамках приближения сильной связи теоретически рассчитаны проводимости контактов вида нормальный металл/изолятор/одноорбитальный сверхпроводник с p-типом сверхпроводящего спаривания (N/I/Sp). Объяснено наблюдаемое экспериментально как появление пика при нулевом напряжении, так и его расщепление в зависимости от толщины слоя изолятора. В рамках этой же микроскопической теории развит вариант техники решеточной функции Грина в мацубаровом представлении. Используя разработанный подход, рассчитаны фазовые и температурные зависимости тока Джозефсона для контакта сверхпроводника s-типа и многозонного железосодержащего сверхпроводника (ферропниктида) для различных ориентаций границы по отношению к кристаллографическим осям пниктида.
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Кардакова, А. И., Финкель, М. И., Морозов, Д. В., Ковалюк, В. В., Ан, П. П., & Гольцман, Г. Н. (2014). Время электрон-фононного взаимодействия в сверхпроводниковых пленках нитрида титана. In Труды XVIII международного симпозиума «Нанофизика и наноэлектроника» (Vol. 1, pp. 47–48).
Abstract: Определены времена электрон-фононного взаимодействия в тонких сверхпроводниковых пленках нитрида титана. Измеренные значения τ_eph находятся в диапазоне от 5.5 нс до 88 нс при температурах 4,2 К и 1,7 К, соответственно, и соответствуют температурной зависимости Т^-3.
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Корнеева, Ю. П., Михайлов, М. М., Манова, Н. Н., Дивочий, А. А., Корнеев, А. А., Вахтомин, Ю. Б., et al. (2014). Сверхпроводниковый однофотонный детектор на основе аморфных пленок MoSi. In Труды XVIII международного симпозиума «Нанофизика и наноэлектроника» (Vol. 1, pp. 53–54).
Abstract: Нами были изготовлены и исследованы однофотонные детекторы на основе сверхпроводящих пленок Mo x Si 1-x двух различных стехиометрий: Mo 3 Si и Mo 4 Si. При температуре 1.7 К лучшие детекторы площадью 7 мкм*7 мкм на основе этих пленок продемонстрировали системную квантовую эффективность 18% при скорости темнового счета 10 с -1 на длине волны 1.2 мкм с использованием неполяризованного источника, длительность импульса – 6 нс, джиттер – 120 пс.
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Kitaygorsky, J., Komissarov, I., Jukna, A., Minaeva, O., Kaurova, N., Divochiy, A., et al. (2007). Fluctuations in two-dimensional superconducting NbN nanobridges and nanostructures meanders. In Proc. APS March Meeting (Vol. 52, L9.00013).
Abstract: We have observed fluctuations, manifested as sub-nanosecond to nanosecond transient, millivolt-amplitude voltage pulses, generated in two-dimensional NbN nanobridges, as well as in extended superconducting meander nanostructures, designed for single photon counting. Both nanobridges and nano-stripe meanders were biased at currents close to the critical current and measured in a range of temperatures from 1.5 to 8 K. During the tests, the devices were blocked from all incoming radiation by a metallic enclosure and shielded from any external magnetic fields. We attribute the observed spontaneous voltage pulses to the Kosterlitz-Thouless-type fluctuations, where the high enough applied bias current reduces the binding energy of vortex-antivortex pairs and, subsequently, thermal fluctuations break them apart causing the order parameter to momentarily reduce to zero, which in turn causes a transient voltage pulse. The duration of the voltage pulses depended on the device geometry (with the high-kinetic inductance meander structures having longer, nanosecond, pulses) while their rate was directly related to the biasing current as well as temperature.
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Gayduchenko, I. A., Moskotin, M. V., Matyushkin, Y. E., Rybin, M. G., Obraztsova, E. D., Ryzhii, V. I., et al. (2018). The detection of sub-terahertz radiation using graphene-layer and graphene-nanoribbon FETs with asymmetric contacts. In Materials Today: Proc. (Vol. 5, pp. 27301–27306).
Abstract: We report on the detection of sub-terahertz radiation using single layer graphene and graphene-nanoribbon FETs with asymmetric contacts (one is the Schottky contact and one – the Ohmic contact). We found that cutting graphene into ribbons a hundred nanometers wide leads to a decrease of the response to sub-THz radiation. We show that suppression of the response in the graphene nanoribbons devices can be explained by unusual properties of the Schottky barrier on graphene-vanadium interface.
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Korneev, A., Korneeva, Y., Florya, I., Voronov, B., & Goltsman, G. (2012). NbN nanowire superconducting single-photon detector for mid-infrared. Phys. Procedia, 36, 72–76.
Abstract: Superconducting single-photon detectors (SSPD) is typically 100 nm-wide supercondiucting strip in a shape of meander made of 4-nm-thick film. To reduce response time and increase voltage response a parallel connection of the strips was proposed. Recently we demonstrated that reduction of the strip width improves the quantum effciency of such a detector at wavelengths longer than 1.5 μm. Being encourage by this progress in quantum effciency we improved the fabrication process and made parallel-wire SSPD with 40-nm-wide strips covering total area of 10 μm x 10 μm. In this paper we present the results of the characterization of such a parallel-wire SSPD at 10.6 μm wavelength and demonstrate linear dependence of the count rate on the light power as it should be in case of single-photon response.
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Zhang, W., Miao, W., Yao, Q. J., Lin, Z. H., Shi, S. C., Gao, J. R., et al. (2012). Spectral response and noise temperature of a 2.5 THz spiral antenna coupled NbN HEB mixer. Phys. Procedia, 36, 334–337.
Abstract: We report on a 2.5 THz spiral antenna coupled NbN hot electron bolometer (HEB) mixers, fabricated with in-situ process. The receiver noise temperature with lowest value of 1180 K is in good agreement with calculated quantum efficiency factor as a function of bias voltage. In addition, the measured spectral response of the spiral antenna coupled NbN HEB mixer shows broad frequency coverage of 0.8-3 THz, and corrected response for optical losses, FTS, and coupling efficiency between antenna and bolometer falls with frequency due to diffraction-limited beam of lens/antenna combination.
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