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Райтович, А. А., Пентин, И. В., Золотов, Ф. И., Селезнев, В. А., Вахтомин, Ю. Б., & Смирнов, К. В. (2018). Время энергетической релаксации электронов в сверхпроводниковых VN наноструктурах. In Сборник трудов 13 Всероссийской конференции молодых ученых (pp. 236–238). Техно-Декор.
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Мошкова, М. А., Дивочий, А. В., Морозов, П. В., Антипов, А. В., Вахтомин, Ю. Б., & Смирнов, К. В. (2019). Оценка статистики распределения фотонов с использованием многоэлементного сверхпроводникового однофотонного детектора. In Межвузовская научно-техническая конференция студентов, аспирантов и молодых специалистов им. Е. В. Арменского (pp. 201–202). МИЭМ НИУ ВШЭ.
Abstract: Проведен сравнительный анализ топологий сверхпроводниковых однофотонных детекторов с способностью к разрешению до четырёх фотонов в коротком импульсе ИК излучения. Получен детектор, с системной квантовой эффективностью ~85% на λ=1550 нм. Продемонстрирована возможность его использования для распределения числа фотонов импульсного источника излучения.
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Золотов, Ф. И., & Смирнов, К. В. (2019). Особенности осаждения разупорядоченных сверхтонких плёнок нитрида ванадия. In Межвузовская научно-техническая конференция студентов, аспирантов и молодых специалистов им. Е. В. Арменского (pp. 204–205). МИЭМ НИУ ВШЭ.
Abstract: В работе изучены особенности роста сверхтонких плёнок нитрида ванадия толщиной ~10 нм. Обнаружено, что при изменении температуры подложки и общего давления газов в процессе осаждения плёнок меняется значение их поверхностного сопротивления вблизи перехода к сверхпроводящему состоянию.
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Ozhegov, R. V., Smirnov, A. V., Vakhtomin, Y. B., Smirnov, K. V., Divochiy, A. V., & Goltsman, G. N. (2009). Ultrafast superconducting bolometer receivers for terahertz applications. In Proc. PIERS (867). 777 Concord Avenue, Suite 207 Cambridge, MA 02138: The Electromagnetics Academy.
Abstract: The research by the group of Moscow State Pedagogical University into the hot-electron phenomena in thin superconducting films has led to the development of new types of detectors and their use both in fundamental and applied studies. In this paper, we present the results of testing the terahertz HEB receiver systems based on ultrathin (∼ 4 nm) NbN and MoRe detectors with a response time of 50 ps and 1 ns, respectively. We have developed three types of devices which differ in the way a terahertz signal is coupled to the detector and cover the following ranges: 0.3–3 THz, 0.1–30 THz and 25–70 THz. In the case of the receiving system optimized for 0.3–3 THz, the sensitive element (a strip of asuperconductor with planar dimensions of 0.2μm (length) by 1.7μm (width)) was integrated witha planar broadband log-spiral antenna. For additional focusing ofthe incident radiation a silicon hyperhemispherical lens was used. For the 0.1–30 THz receivingsystem, the sensitive element was patterned as parallel strips(2μm wide each) filling an area of 500×500μm2with a filling factor of 0.5. In the receivingsystem of this type we used direct coupling of the incident radiation to the sensitive element. Inthe 25–70 THz range (detector type 2/2a in Table 1) we used a square-shaped superconductingdetector with planar dimensions of 10×10μm2. Incident radiation was coupled to the detectorwith the use of a germanium hyperhemispherical lens.The response time of the above receiving systems is determined by the cooling rate of the hotelectrons in the film. That depends on the electron-phonon interaction time, which is less forultrathin NbN than in MoRe.
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Kovaluyk, V., Lazarenko, P., Kozyukhin, S., An, P., Prokhodtsov, A., Goltsman, G., et al. (2019). Influence of the phase state of Ge2Sb2Te5 thin cover on the parameters of the optical waveguide structures. In Proc. Amorphous and Nanostructured Chalcogenides (pp. 47–48). Technical University of Moldova.
Abstract: The fast switching time of Ge-Sb-Te thin films between amorphous and crystalline states initiated by laser beam as well as significant change of their optical properties and the preservation of metastable states for tens of years open wide perspectives for the application of these materials to fully optical devices [1], including high-speed optical memory [2]. Here we study optical properties of the Ge2Sb2Te5 (GST225) thin films integrated with on-chip silicon nitride O-ring resonator. The rib waveguide of the resonator was formed the first stage of e-beam lithography and subsequent reactive-ion etching. We used the second stage of e-beam lithography combining with lift-off method for the formation of GST225 active region on the resonator ring surface. The amorphous GST225 thin films were prepared by magnetron sputtering, and were capped by thin silicon oxide on their tops. The length of the GST225 active region varied from 0.1 to 20 μ m. Crystallization of amorphous thin films was carried out at the temperature of 400 °C for 30 minutes. Auger electron spectroscopy and transmission electron microscopy were used for studying composition and structure of investigated GST225thin films, respectively. It was observed that crystallization of amorphous GST225 film lead to a decrease of the optical power, transmitted through the waveguide. Comparison of the optical transmittance of O-ring resonators before and after the GST225 deposition allowed to identify the change in the Q-factor and the wavelength peak shift. This can be explained by the differences of the complex refractive indexes of GST225 thin films in the amorphous and crystalline states. From the measurement data, the GST225 effective refractive index was extracted depending on the ring waveguide width of the resonator for a telecommunication wavelength of 1550 nm.
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