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Финкель, М. И., Масленников, С. Н., & Гольцман, Г. Н. (2007). Концепция приёмного комплекса космического радиотелескопа «Миллиметрон». Известия высших учебных заведений. Радиофизика, 50(10-11), 924–934.
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Kawamura, J., Blundell, R., Tong, C. - Y. E., Papa, D. C., Hunter, T. R., Paine, St. N., et al. (2000). Superconductive hot-electron bolometer mixer receiver for 800 GHz operation (Vol. 48).
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Финкель, М. И., Масленников, С. Н., & Гольцман, Г. Н. (2005). Супергетеродинные терагерцовые приёмники со сверхпроводниковым смесителем на электронном разогреве. Известия высших учебных заведений. Радиофизика, 48(10), 964–970.
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Gol'tsman, G., Korneev, A., Minaeva, O., Antipov, A., Divochiy, A., Kaurova, N., et al. (2006). Middle-infrared to visible-light ultrafast superconducting single-photon detector. In Proc. ASC. Seattle.
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Гершензон, Е. М., Гершензон, М. Е., Гольцман, Г. Н., Семенов, А. Д., & Сергеев, А. В. (1982). Неселективное воздействие электромагнитного излучения на сверхпроводящую пленку в резистивном состоянии. Письма в ЖЭТФ, 36(7), 241–244.
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Гершензон, Е. М. (1982). Воздействие электромагнитного излучения на сверхпроводящую плёнку ниобия в резистивном состоянии. In Тезисы докладов 22 Всесоюзной конференции по физике низких температур (pp. 79–80).
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Yagoubov, P., Kroug, M., Merkel, H., Kollberg, E., Schubert, J., Hubers, H. W., et al. (1999). Hot electron bolometric mixers based on NbN films deposited on MgO substrates. In Inst. Phys. Conf. Ser. (Vol. 167, pp. 687–690). Barcelona, Spain.
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Maslennikov, S., Antipov, S., Shishkov, A., Svechnikov, S., Voronov, B., Smirnov, K., et al. (2002). NbN HEB mixer noise temperature measurements with hot/cold load mounted inside the helium cryostat at 300 GHz. In Proc. Int. Student Seminar on Microwave Appl. of Novel Physical Phenomena supported by IEEE. St.-Petersburg: LETI.
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Ozhegov, R., Morozov, D., Maslennikov, S., Okunev, O., Smirnov, K., & Gol'tsman, G. (2004). Submillimeter wave range imaging system for registering human body radiation and finding out the things covered under clothes. In Proc. 3rd Int. exhibition and conf. Non-Destructive Testing Equipment and Devices. Moscow.
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Ожегов, Р. В., Морозов, Д. В., Масленников, С. Н., Смирнов, К. В., Окунев, О. В., & Гольцман, Г. Н. (2004). Тепловизор субмиллиметрового диапазона волн для регистрации теплового излучения тела человека и обнаружения скрытых под одеждой предметов. In 3-я Международная выставка и конференция Неразрушающий контроль и техническая диагностика в промышленности. Москва.
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Ozhegov, R., Maslennikov, S., Morozov, D., Okunev, O., Smirnov, K., & Gol'tsman, G. (2004). Imaging system for submillimeter wave range. In Proc. Tenth All-Russian sceintific conference of student-physicists and young sceintists (VNKSF-10). Moscow.
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Ожегов, Р. В., Масленников, С. Н., Морозов, Д. В., Окунев, О. В., Смирнов, К. В., & Гольцман, Г. Н. (2004). Тепловизор субмиллиметрового диапазона длин волн. In Десятая всероссийская научная конференция студентов-физиков и молодых ученых (ВНКСФ-10). Москва.
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Maslennikov, S., Vachtomin, Y., Antipov, S., Smirnov, K., Kaurova, N., Grishina, E., et al. (2004). NbN HEB mixers for frequencies of 2.5 and 3.8 THz. In Proc. Tenth All-Russian sceintific conference of student-physicists and young sceintists (VNKSF-10). Moscow.
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Масленников, С. Н., Вахтомин, Ю. Б., Антипов, С. В., Смирнов, К. В., Каурова, Н. С., Гришина, Е. В., et al. (2004). Смесители на основе электронного разогрева в тонких пленках NbN для частот 2.5 и 3.8 ТГц. In Десятая всероссийская научная конференция студентов-физиков и молодых ученых (ВНКСФ-10). Москва.
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Vachtomin, Y. B., Antipov, S. V., Kaurova, N. S., Maslennikov, S. N., Smirnov, K. V., Polyakov, S. L., et al. (2004). Noise temperature, gain bandwidth and local oscillator power of NbN phonon-cooled HEB mixer at terahertz frequenciess. In Proc. 29th IRMMW / 12th THz (pp. 329–330). Karlsruhe, Germany.
Abstract: We present the performances of HEB mixers based on 3.5 nm thick NbN film integrated with log-periodic spiral antenna. The double side-band receiver noise temperature values are 1300 K and 3100 K at 2.5 THz and at 3.8 THz, respectively. The gain bandwidth of the mixer is 4.2 GHz and the noise bandwidth is 5 GHz. The local oscillator power is 1-3 /spl mu/W for mixers with different active area.
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Каурова, Н. С., Финкель, М. И., Масленников, С. Н., Вахтомин, Ю. Б., Антипов, С. В., Смирнов, К. В., et al. (2004). Смеситель субмиллиметрового диапазона длин волн на основе тонкой пленки YBa2Cu3O7-x. In 1-я международная конференция Фундаментальные проблемы высокотемпературной сверхпроводимости (291). Москва-Звенигород.
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Корнеев, А. А. (2006). Квантовая эффективность и темновой счет NbN сверхпроводникового инфракрасного однофотонного детектора. Ph.D. thesis, , .
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Морозов, Д. В. (2007). Приемные устройства терагерцового диапазона на эффекте разогрева двумерного электронного газа в гетероструктурах AlGaAs/GaAs. Ph.D. thesis, , .
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Maslennikova, A., Tretyakov, I., Ryabchun, S., Finkel, M., Kaurova, N., Voronov, B., et al. (2010). Gain bandwidth and noise temperature of NbN HEB mixers with simultaneous phonon and diffusion cooling. In Proc. 21th Int. Symp. Space Terahertz Technol. (pp. 218–219).
Abstract: The space observatory Millimetron will be operating in the millimeter, sub-millimeter and infrared ranges using a 12-m cryogenic telescope in a single-dish mode, and as an interferometer with the space-earth and space-space baselines (the latter after the launch of the second identical space telescope). The observatory will allow performing astronomical observations with an unprecedented sensitivity (down to nJy level) in the single-dish mode, and observations with a high angular resolution in the interferometer mode. The total spectral range 20 μm – 2 cm is separated into 10 bands. HEB mixers with two cooling channels (diffusion and phonon) have been chosen to be the detectors of choice of the system covering the range from 1 THz to 6 THz as the best detectors in terahertz receivers. This type of HEB has already shown good work in the terahertz range. A gain bandwidth of 6 GHz at an LO frequency of 300 GHz and a noise temperature of 750 K at an LO frequency of 2.5 THz are the best values for HEB mixers with two cooling channels [1]. Theoretical estimations predict a bandwidth up to 12 GHz. Reaching such good result demands more systematic and thorough research. We present the results of the gain bandwidth and noise temperature measurements for superconducting hot- electron bolometer mixers with two cooling channels. These characteristics of the devices of lengths varying from 50 to 200 nm were measured for the purposes of Millimetron at frequencies of 600 GHz, 2.5 THz, and 3.8 THz. For gain bandwidth measurements we use two BWO’s operating at 600 GHz: one as the signal and the second as the LO. The noise temperature measurements were performed using a gas discharge laser as the LO and blackbodies at 77 K and 295 K as input signals. The devices studied consist of 3.5-nm-thick NbN bridges connected to thick (10 nm) high conductivity Au leads fabricated in situ. This method of fabricating devices has already proved promising by opening the diffusion cooling channel. [2] Fig. 1 shows a SEM photograph of a log-spiral antenna with an HEB at its apex. Fig. 1. Left: a SEM photograph of a log-spiral antenna with an HEB at its apex; right: a close-up of the HEB at the antenna apex. [1] S. A. Ryabchun, I. V. Tretyakov, M. I. Finkel, S. N. Maslennikov, N. S. Kaurova, V. A. Seleznev, B. M. Voronov, and G. N. Gol’tsman, NbN phonon-cooled hot-electron bolometer mixer with additional diffusion cooling, Proc. of the 20 th Int. Symp. Space. Technol., Charlottesville, Virginia, USA, April 20 – 22, 2009. 218[2] S. A. Ryabchun * , I. V. Tretyakov, M. I. Finkel, S. N. Maslennikov, N. S. Kaurova, V. A. Seleznev, B. M. Voronov and G. N. Goltsman, Fabrication and characterisation of NbN HEB mixers with in situ gold contacts, Proc. of the 19 th Int. Symp. Space. Technol., Groningen, The Netherlands, April 28-30, 2008
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Третьяков, И. В., Рябчун, С. А., Каурова, Н. С., Ларионов, П. А., Лобастова, А. А., Воронов, Б. М., et al. (2010). Оптимальная поглощенная мощность гетеродина для терагерцового сверхпроводникового NbN смесителя на электронном разогреве. Письма в ЖТФ, 36(23), 78–84.
Abstract: Представлены результаты измерений поглощенной мощности гетеродина малошумящим широкополосным смесителем на эффекте электронного разогрева в резистивном состоянии сверхпроводниковой ультратонкой пленки NbN. Оптимальная поглощенная мощность гетеродина составила около 100 nW на частоте 2.5 THz.
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Ожегов, Р. В., Горшков, К. Н., Окунев, О. В., & Гольцман, Г. Н. (2010). Сверхпроводниковый смеситель на эффекте электронного разогрева как элемент матрицы системы построения тепловых изображений. Письма в ЖТФ, 36(21), 70–78.
Abstract: Исследована возможность использования матрицы чувствительных элементов на гиперполусферической линзе диаметром 12 mm в тепловизоре терагерцевого диапазона частот. Получены размеры области на линзе, приемлемой для расположения матрицы, в которой шумовая температура приемника меняется в пределах 16% от средней. Диаметр этой области составил 3.3% диаметра линзы.Получены отклонения основного лепестка диаграммы направленности, которые составили ±1.25â—<a6> от направления с оптимальным положением смесителя. Флуктуационная чувствительность приемника в эксперименте составила 0.5 K на частоте 300 GHz.
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Ожегов, Р. В., Окунев, О. В., Гольцман, Г. Н., Филиппенко, Л. В., & Кошелец, В. П. (2009). Флуктуационная чувствительность сверхпроводящего интегрального приемника терагерцового диапазона частот. Радиотех. электроник., 54(6), 750–755.
Abstract: Исследована зависимость флуктуационной чувствительности сверхпроводящего интегрального приемника (СИП) от шумовой температуры приемника и величины входного сигнала. Измерена рекордная флуктуационная чувствительность приемника (13 ± 2 мК), полученная при шумовой температуре приемника 200 К, ширине полосы промежуточных частот 4 ГГц и постоянной времени 1 с. При уменьшении входного сигнала наблюдалось улучшение флуктуационной чувствительности; предложено обÑŠяснение полученного эффекта: причиной является уменьшение влияния нестабильностей источников питания приемника и усилительного тракта при снижении входного сигнала.
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Расулова, Г. К., Брунков, П. Н., Пентин, И. В., Ковалюк, В. В., Горшков, К. Н., Казаков, А. Ю., et al. (2011). Взаимная синхронизация двух связанных генераторов автоколебаний на основе сверхрешеток GaAs/AlGaAs. ЖТФ, 81(6), 80–86.
Abstract: Проведено исследование взаимодействия генераторов автоколебаний на основе 30-периодной слабосвязанной сверхрешетки GaAs/AlGaAs. Воздействие одного генератора автоколебаний на другой осуществлялось при заданном постоянном смещении в отсутствие в одном из них генерации автономных колебаний. Показано, что вынужденные колебания в захватывающем генераторе возникают из-за возбуждения колебаний в системе связанных осцилляторов, образующих границу электрополевого домена на частоте одной из высших гармоник вынуждающего колебания.
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Гольцман, Г. Н., Разумовская, И. В., Окунев, О. В., Чулкова, Г. М., Корнеев, А. А., Финкель, М. И., et al. (2011). Сборник программ учебных дисциплин профессионального цикла подготовки магистров и бакалавров по направлению «Физика». Прометей, , 67.
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Смирнов, А. В. (2009). Исследование полосы преобразования терагерцовых смесителей на эффекте электронного разогрева в NbZr, NbN и в одиночном гетеропереходе AlGaAs/GaAs.
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Seleznev, V. A., Tarkhov, M. A., Voronov, B. M., Milostnaya, I. I., Lyakhno, V. Y., Garbuz, A. S., et al. (2008). Deposition and characterization of few-nanometers-thick superconducting Mo-Re films. Supercond. Sci. Technol., 21(11), 115006 (1 to 6).
Abstract: We report on the fabrication and investigation of few-nanometers-thick superconducting molybdenum-rhenium (Mo-Re) films intended for use in nanowire single-photon superconducting detectors (SSPDs). Mo-Re films were deposited on sapphire substrates by DC magnetron sputtering of an Mo(60)-Re(40) alloy target in an atmosphere of argon. The films 2-10 nm thick had critical temperatures (Tc) from 5.6 to 9.7 K. HRTEM (high-resolution transmission electron microscopy) analysis showed that the films had a homogeneous structure. XPS (x-ray photoelectron spectroscopy) analysis showed the Mo to Re atom ratio to be 0.575/0.425, oxygen concentration to be 10%, and concentration of other elements to be 1%.
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Bell, M., Sergeev, A., Mitin, V., Bird, J., Verevkin, A., & Gol'tsman, G. (2007). One-dimensional resistive states in quasi-two-dimensional superconductors. arXiv:0709.0709v1 [cond-mat.supr-con], , 1–11.
Abstract: We investigate competition between one- and two-dimensional topological excitations – phase slips and vortices – in formation of resistive states in quasi-two-dimensional superconductors in a wide temperature range below the mean-field transition temperature T(C0). The widths w = 100 nm of our ultrathin NbN samples is substantially larger than the Ginzburg-Landau coherence length ξ = 4nm and the fluctuation resistivity above T(C0) has a two-dimensional character. However, our data shows that the resistivity below T(C0) is produced by one-dimensional excitations, – thermally activated phase slip strips (PSSs) overlapping the sample cross-section. We also determine the scaling phase diagram, which shows that even in wider samples the PSS contribution dominates over vortices in a substantial region of current/temperature variations. Measuring the resistivity within seven orders of magnitude, we find that the quantum phase slips can only be essential below this level.
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Dzardanov, A., Ekstrom, H., Gershenzon, E., Gol'tsman, G., Jacobsson, S., Karasik, B., et al. (1994). Hot-electron superconducting mixers for 20-500 GHz operation. In Proc. Int. Conf. on Millimeter and Submillimeter Waves and Appl. (Vol. 2250, pp. 276–278).
Abstract: Bolometdcmucers based on Nb and NbN superconducting thin films in the resistive state have been prepared for 20, 100 GHz and 350-500 GHz operation. The mixing mechanism is presumably of electron heating origin. Our measurements indicate that a conversion loss of about 6-8 dB can rather easily be achieved, and that the noise is reasonably low. The requirements on the operation mode and on the film parameters in order to obtain small conversion losses or even gain are discussed. For NbN films the availability of nearly 1 GHz IF bandwidth is experimentally demonstrated. NbN hot-electron mucers combined with slot-line tapered antenna on Si membrane or with double-dipole antenna on SiO^ substrate have been fabricated. The devices we study are considered to be very promising for use in heterodyne receivers from microwaves to terahertz frequencies.
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Gershenzon, E. M., Il'in, V. A., Litvak-Gorskaya, L. B., & Filonovich, S. R. (1979). Character of submillimeter photoconductivity in n-lnSb. Sov. Phys. JETP, 49(1), 121–128.
Abstract: A comprehensive investigation was made of the submillimeter photoconductivity of n -1nSb in the range of wavelengths L = 0.6-8 mm, magnetic fields H = 0-30 kOe, electric fields E = 0.01-0.5 V/cm, and temperatures T = 1.3-30 K. The kinetics of the photoconductivity processes as a function of T, E; and H is investigated. It is shown that impurity photoconductivity does exist for any degree of compensation of extremely purified n-InSb. Particular attention is paid to the hopping photoconductivity realized in strongly compensated n-1nSb (K > 0.8).
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Ptitsina N. G., Chulkova G. M., Il'in K. S., Sergeev A. V., Pochinkov F. S., & Gershenzon E. M. (1997). Superconductivity has been found in a number of new compounds between the non-superconducting transition elements and nonmetals such as Si, Ge, and Te. These findings have suggested possible criteria for superconductivity in both elements and compounds. Phys. Rev. B, 56(16).
Abstract: The temperature dependence of the resistance of films of Al, Be, and NbC with small values of the electron mean free path L=1.5– 10 nm has been measured at 4.2–300 K. The resistance of all the films contains a T^2 contribution that is proportional to the residual resistance; this contribution has been attributed to the interference between the elastic electron scattering and the electron-phonon scattering. Fitting the data to the theory of the electron-phonon-impurity interference „M. Yu. Reiser and A. V. Sergeev, Zh. Eksp. Teor. Fiz. 92, 224 ~1987! @Sov. Phys. JETP 65, 1291 ~1987!#…, we obtain constants of nteraction of the electrons with transverse phonons, and estimate the contribution of this interaction to the electron dephasing rate in thin films of Au, Al, Be, Nb, and NbC. Our estimates are in a good agreement with the experimental data on the inelastic electronphonon scattering in these films. This indicates that the interaction of electrons with transverse phonons controls the electron-phonon relaxation rate in thin-metal films over a broad temperature range.
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Ptitsina, N. G., Chulkova, G. M., & Gershenzon, E. M. (1995). Influence of the interference of electron-phonon and electron-impurity scattering on the conductivity of unordered Nb films. JETP, 80(5), 960–964.
Abstract: The temperature dependence of the resistivity of Nb thin films has been studied at T=4.2-300 K. It has been shown that quantum interference between electron-phonon and electron-impurity scattering determines the temperature dependence of the resistivity of the films investigated over a broad temperature range. The magnitude of the contribution of the electron-phonon-impurity,interference is described satisfactorily by the theory developed by Reizer and Sergeev {Zh. Eksp. Teor. Fiz. 92,2291 (1987) [Sov. Phys. JETP 65, 1291 (1987)l). The interaction constants of electrons with longitudinal and transverse phonons in Nb films have been determined for the first time by comparing the experimental data with the theory. The values of the constants obtained are consistent with the data on the inelastic electron-phonon scattering times in the films investigated. The contribution of the transverse phonons is dominant both in the interference correction to the resistivity and in the electron energy relaxation.
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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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Smirnov, K., Vachtomin, Y., Divochiy, A., Antipov, A., & Goltsman, G. (2015). Dependence of dark count rates in superconducting single photon detectors on the filtering effect of standard single mode optical fibers. Appl. Phys. Express, 8(2), 022501 (1 to 4).
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Sidorova, M. V., Divochiy, A., Vakhtomin, Y. B., & Smirnov, K. V. (2015). Ultrafast superconducting single-photon detector with reduced-size active area coupled to a tapered lensed single-mode fiber. In International Society for Optics and Photonics (Ed.), Proc. SPIE (Vol. 9504, 950408 (1 to 9)).
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Elezov, M. S., Ozhegov, R. V., Goltsman, G. N., & Makarov, V. (2017). Development of the experimental setup for investigation of latching of superconducting single-photon detector caused by blinding attack on the quantum key distribution system. In EPJ Web of Conferences (Vol. 132, 2).
Abstract: Recently bright-light control of the SSPD has been
demonstrated. This attack employed a “backdoor†in the detector biasing
scheme. Under bright-light illumination, SSPD becomes resistive and
remains “latched†in the resistive state even when the light is switched off.
While the SSPD is latched, Eve can simulate SSPD single-photon response
by sending strong light pulses, thus deceiving Bob. We developed the
experimental setup for investigation of a dependence on latching threshold
of SSPD on optical pulse length and peak power. By knowing latching
threshold it is possible to understand essential requirements for
development countermeasures against blinding attack on quantum key
distribution system with SSPDs.
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Peltonen, J. T., Peng, Z. H., Korneeva, Y. P., Voronov, B. M., Korneev, A. A., Semenov, A. V., et al. (2016). Coherent dynamics and decoherence in a superconducting weak link. Physic. Rev. B,, 94, 180508.
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Tretyakov, I., Shurakov, A., Perepelitsa, A., Kaurova, N., Svyatodukh, S., Zilberley, T., et al. (2019). Room temperature silicon detector for IR range coated with Ag2S quantum dots. Phys. Status Solidi RRL, 13(9), 1900187–(1–6).
Abstract: For decades, silicon has been the chief technological semiconducting material of modern microelectronics and has a strong influence on all aspects of the society. Applications of Si-based optoelectronic devices are limited to the visible and near infrared (IR) ranges. For photons with an energy less than 1.12 eV, silicon is almost transparent. The expansion of the Si absorption to shorter wavelengths of the IR range is of considerable interest for optoelectronic applications. By creating impurity states in Si, it is possible to cause sub-bandgap photon absorption. Herein, an elegant and effective technology of extending the photo-response of Si toward the IR range is presented. This approach is based on the use of Ag 2 S quantum dots (QDs) planted on the surface of Si to create impurity states in the Si bandgap. The specific sensitivity of the room temperature zero-bias Si_Ag 2 Sp detector is 10 11 cm Hz W 1 at 1.55 μm. Given the variety of available QDs and the ease of extending the photo-response of Si toward the IR range, these findings open a path toward future studies and development of Si detectors for technological applications. The current research at the interface of physics and chemistry is also of fundamental importance to the development of Si optoelectronics.
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Shurakov, A., Mikhalev, P., Mikhailov, D., Mityashkin, V., Tretyakov, I., Kardakova, A., et al. (2018). Ti/Au/n-GaAs planar Schottky diode with a moderately Si-doped matching sublayer. Microelectronic Engineering, 195, 26–31.
Abstract: In this paper, we report on the results of the study of the Ti/Au/n-GaAs planar Schottky diodes (PSD) intended for the wideband detection of terahertz radiation. The two types of the PSD devices were compared having either the dual n/n+ silicon dopant profile or the triple one with a moderately doped matching sublayer inserted. All the diodes demonstrated no noticeable temperature dependence of ideality factors and barrier heights, whose values covered the ranges of 1.15–1.50 and 0.75–0.85 eV, respectively. We observed the lowering of the flat band barrier height of ∼80 meV after introducing the matching sublayer into the GaAs sandwich. For both the devices types, the series resistance value as low as 20 Ω was obtained. To extract the total parasitic capacitance, we performed the Y-parameters analysis within the electromagnetic modeling of the PSD's behavior via the finite-element method. The capacitance values of 12–12.2 fF were obtained and further verified by measuring the diodes' response voltages in the frequency range of 400–480 GHz. We also calculated the AC current density distribution within the layered structures similar to those being experimentally studied. It was demonstrated that insertion of the moderately Si-doped matching sublayer might be beneficial for implementation of a PSD intended for the operation within the ‘super-THz’ frequency range.
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Divochiy, A., Misiaszek, M., Vakhtomin, Y., Morozov, P., Smirnov, K., Zolotov, P., et al. (2018). Single photon detection system for visible and infrared spectrum range. Opt. Lett., 43(24), 6085–6088.
Abstract: We demonstrate niobium nitride based superconducting single-photon detectors sensitive in the spectral range 452-2300 nm. The system performance was tested in a real-life experiment with correlated photons generated by means of spontaneous parametric downconversion, where one photon was in the visible range and the other was in the infrared range. We measured a signal to noise ratio as high as 4x10(4) in our detection setting. A photon detection efficiency as high as 64% at 1550 nm and 15% at 2300 nm was observed.
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Zolotov, P., Divochiy, A., Vakhtomin, Y., Seleznev, V., Morozov, P., & Smirnov, K. (2018). Superconducting single-photon detectors made of ultra-thin VN films. In KnE Energy (Vol. 3, pp. 83–89).
Abstract: We optimized technology of thin VN films deposition in order to study VN-based superconducting single-photon detectors. Investigation of the main VN film parameters showed that this material has lower resistivity compared to commonly used NbN. Fabricated from obtained films devices showed 100% intrinsic detection efficiency at 900 nm, at the temperature of 1.7 K starting with the bias current of 0.7·I
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Saveskul, N. A., Titova, N. A., Baeva, E. M., Semenov, A. V., Lubenchenko, A. V., Saha, S., et al. (2019). Superconductivity behavior in epitaxial TiN films points at surface magnetic disorder. arXiv:1903.05009v3 [cond-mat.mtrl-sci]. Retrieved May 15, 2024, from https://arxiv.org/abs/1903.05009v3
Abstract: We analyze the evolution of the normal and superconducting electronic properties in epitaxial TiN films, characterized by high Ioffe-Regel parameter values, as a function of the film thickness. As the film thickness decreases, we observe an increase of in the residual resistivity, which becomes dominated by diffusive surface scattering for d≤20nm. At the same time, a substantial thickness-dependent reduction of the superconducting critical temperature is observed compared to the bulk TiN value. In such a high quality material films, this effect can be explained by a weak magnetic disorder residing in the surface layer with a characteristic magnetic defect density of ∼1012cm−2. Our results suggest that surface magnetic disorder is generally present in oxidized TiN films.
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Bandurin, D., Svintsov, D., Gayduchenko, I., Xu, S., Principi, A., Moskotin, M., et al. (2019). Resonant terahertz photoresponse and superlattice plasmons in graphene field-effect transistors. In APS March Meeting (F14.015).
Abstract: Plasmons, collective oscillations of electron systems, can couple light and electric current, and thus can be used to create compact photodetectors, radiation mixers, and spectrometers. Despite the effort, it has proven challenging to implement plasmonic devices operating at THz frequencies. The material capable to meet this challenge is graphene as it supports long-lived electrically-tunable plasmons. In this talk, we will demonstrate plasmon-assisted resonant detection of THz radiation by antenna-coupled graphene FETs that act as both rectifying elements and plasmonic Fabry-Perot cavities amplifying the photoresponse. We will show that by varying the plasmon velocity using gate voltage, our detectors can be tuned between multiple resonant modes, a functionality that we apply to measure plasmons' wavelength and lifetime in graphene as well as to probe collective modes in its moire minibands. Our approach offers a convenient tool for further plasmonic research that is often difficult under non-ambient conditions and promises a viable route for various THz applications. We acknowledge Leverhulme Trust, Russian Science Foundation Grants N18-72-00234 and 17-72-30036, Russian Foundation for Basic Research No. 18-57-06001 and 16-29-03402.
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Korneev, A., Semenov, A., Vodolazov, D., Gol’tsman, G. N., & Sobolewski, R. (2017). Physics and operation of superconducting single-photon devices. In R. Wördenweber, V. Moshchalkov, S. Bending, & F. Tafuri (Eds.), Superconductors at the Nanoscale (pp. 279–308). De Gruyter.
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Mehdi, I., Gol'tsman, G., & Putz, P. (2015). Introduction to the mini-special-issue on the 25th international symposium on space terahertz technology (ISSTT) (Vol. 5).
Abstract: THE 25th International Symposium on Space Terahertz Technology (ISSTT) was held in Moscow, Russia, between April 27–30, 2014. The conference was organized by Moscow State Pedagogical University and the Higher School of Economics (National Research University) and Chaired by Professor Gregory Gol'tsman of Moscow State Pedagogical University. The conference was attended by roughly 150 participants from 15 countries. The technology covered by ISSTT includes detectors, devices, circuits and systems in various areas of THz science and technology. Each year this symposium brings together the global THz space science technology community, and as such, emphasizes the broad international collaboration that is required to execute these large complicated instrument programs that dominate this field. However, talks covering technologies for balloon, aircraft, and ground-based telescopes were also presented.
In this special section of IEEE Transactions on Terahertz Science and Technology, we include eight expanded papers from the 25th ISSTT symposium. The papers range from development of SIS mixers to optical adjustment systems for radio telescopes. The 26th ISSTT will be held in Boston, MA, USA, during March 16–18, 2015. Researchers and scientist involved in THz research are invited to attend this symposium (more details are at http://www.cfa.harvard.edu/events/2015/isstt2015/).
You can access the full list of papers presented at the ISSTT symposia from the National Radio Astronomy Observatory website: http://www.nrao.edu/meetings/isstt/index.shtml
Yours sincerely
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Lobanov, Y. V., Tong, C. -yu E., Hedden, A. S., Blundell, R., & Gol’tsman, G. N. (2010). Microwave-assisted measurement of the frequency response of terahertz HEB mixers with a Fourier transform spectrometer. In Proc. 21th Int. Symp. Space Terahertz Technol. (pp. 420–423).
Abstract: We describe a novel method of operation of the HEB direct detector for use with a Fourier Transform Spectrometer. Instead of elevating the bath temperature, we have measured the RF response of waveguide HEB mixers by applying microwave radiation to select appropriate bias conditions. In our experiment, a microwave signal is injected into the HEB mixer via its IF port. By choosing an appropriate injection level, the device can be operated close to the desired operating point. Furthermore, we have shown that both thermal biasing and microwave injection can reproduce the same spectral response of the HEB mixer. However, with the use of microwave injection, there is no need to wait for the mixer to reach thermal equilibrium, so characterisation can be done in less time. Also, the liquid helium consumption for our wet cryostat is also reduced. We have demonstrated that the signal- to-noise ratio of the FTS measurements can be improved with microwave injection.
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Goltsman, G. N. (2006). Submillimeter superconducting receivers for astronomy, atmospheric studies and other applications. In 31nd IRMW / 14th ICTE (177).
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Bryerton, E., Percy, R., Bass, R., Schultz, J., Oluleye, O., Lichtenberger, A., et al. (2005). Receiver measurements of pHEB beam lead mixers on 3-μm silicon. In Proc. 30th IRMMW / 13th THz (pp. 271–272).
Abstract: We report on receiver noise measurement results of phonon-cooled HEB beam lead mixers on 3 μm thick silicon. This type of ultra-thin mixer chip with integrated beam leads allows easy assembly into a block and holds great promise for array integration. Receiver measurements from 600-720 GHz are presented with a minimum noise temperature of 500 K at 666 GHz. These results verify the mixer performance of the SOI processing techniques allowing for further design and integration of SOI pHEB mixers in receivers operating above 1 THz.
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Semenov, A., Hübers, H. - W., Richter, H., Birk, M., Krocka, M., Mair, U., et al. (2002). Performance of terahertz heterodyne receiver with a superconducting hot-electron mixer. In Proc. 13th Int. Symp. Space Terahertz Technol. (pp. 229–234).
Abstract: During the past decade major advances have been made regarding low noise mixers for terahertz heterodyne receivers. State of the art hot-electron-bolometer (HEB) mixers have noise temperatures close to the quantum limit and require less than a microwatt power from the local oscillator (L0). The technology is now at a point where the performance of a practical receiver employing such mixer, rather than the figures of merit of the mixer itself, is of major concern. We have incorporated a phonon-cooled NbN HEB mixer in a 2.5 THz heterodyne receiver and investigated its performance. This yields important information for future development of heterodyne receivers such as GREAT (German receiver for astronomy at THz frequencies aboard SOFIA) [1] and TELIS (Terahertz limb sounder), a balloon borne heterodyne receiver for atmospheric research [2]. Both are currently under development at DLR.
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Gershenzon, E. M., & Gol'tsman, G. N. (1993). Hot-electron superconducting mixers. In J. R. Birch, & T. J. Parker (Eds.), Proc. SPIE (Vol. 2104, pp. 329–330). SPIE.
Abstract: The creation of low noise heterodyne receivers for frequencies above 1 THz is in the urgentneed for radio astronomy, laser spectroscopy, plasma diagnostic, etc. In this paper we discussthe nonlinear effect related to hot electrons in superconductors, and their potential use in lownoise submilimeter wave mixer. We also discuss results achieved so far as well as possible futuredevelopments.
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Gershenzon, E. M., & Gol'tsman, G. N. (1988). Effect of electromagnetic radiation on a superconductor in a magnetic field. In Izv. Akad. Nauk SSSR, Seriya Fizicheskaya (Vol. 52, pp. 449–451).
Abstract: The effect of electromagnetic radiation on thin superconducting films of Nb with a large number of static defects is investigated experimentally for the case where the film is in the resistive state due to an applied magnetic field and transport current. The results obtained are found to be well described by a model of spatially homogeneous electron heating. It is noted that the results obtained here for Nb films are also valid for Al, NbN, and MoRe films.
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Gershenzon, E., Gershenzon, M. E., Gol'tsman, G. N., Semenov, A. D., & Sergeev, A. V. (1981). Heating of quasiparticles in a superconducting film in the resistive state. JETP Lett., 34(5), 268–271.
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Goltsman, G. (1972). Simple method for stabilizing power of submillimetric spectrometer. Pribory i Tekhnika Eksperimenta, (1), 136.
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Goltsman, G. N. (2021). Development and applications of terahertz hot electron bolometers. In 1st Moscow Int. Conf. on Submillimeter and Millimeter Astronomy: Objectives and Instruments.
Abstract: The development of techniques and technologies for the deposition of ultrathin superconducting films, the creation of superconducting structures on a nanometer scale is the basis of significant progress in the field of superconducting receiving systems. Ultrathin NbN films are the basis for a wide range of record-breaking hot electron devices: direct and heterodyne terahertz detectors. Terahertz receivers are especially in demand in high-resolution spectroscopy for astronomical, atmospheric, and medical research. HEB receivers are widely used in terahertz radio astronomy. For example, the Dutch SRON Institute is preparing a project for the GUSTO hot air balloon telescope with a HEB mixer array at 1.4 THz and 1.9 THz. A 5-meter Chinese terahertz telescope DATE5 with HEB mixers at 1.4 THz is installed at the South Pole. The Stratospheric Observatory (SOFIA) uses HEB mixer matrices in the GREAT instrument operating in the 1.2 – 4.7 THz range. It is planned to implement the international project Origins Space Telescope (OST) in the far infrared region based on HEB receivers. The Japanese project Smiles-2 will allow measurements at 1.8 THz in the upper layers of the stratosphere and mesosphere. The development of the Millimetron space observatory continues in Russia.
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Elmanov, I., Elmanova, A., Kovalyuk, V., An, P., & Goltsman, G. (2020). Silicon nitride photonic crystal cavity coupled with NV-centers in nanodiamonds. In Proc. 32-nd EMSS (pp. 344–348).
Abstract: The development of integrated quantum photonics requires a high efficient excitation and coupling of a single photon source with on-chip devices. In this paper, we show our results of modelling for high-Q photonic crystal cavity, optimized for zero phonon line emission of NV-centers in nanodiamonds. Modelling was performed for the silicon nitride platform and obtained a quality factor equals to 6136 at 637 nm wavelength.
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Гольцман, Г. Н., Корнеев, А. А., Антипов, А. В., Минаева, О. В., Дивочий, А. В., Антипов, С. В., et al. (2014). Способ фильтрации фонового излучения инфракрасного диапазона.
Abstract: Изобретение относится к способам уменьшения интенсивности фонового излучения инфракрасного диапазона. Способ фильтрации фонового излучения инфракрасного диапазона, падающего на сверхпроводниковый однофотонный детектор, включает передачу излучения инфракрасного диапазона с длиной волны 0,4-1,8 микрометров на сверхпроводниковый однофотонный детектор при помощи одномодового волокна, частично находящегося при температуре 4,0-4,4 К. При этом длина охлаждаемого участка одномодового волокна составляет 0,2-3,5 м. Технический результат заключается в повышении надежности работы фотонных детекторов. 2 з.п. ф-лы.
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Антипов, А. В., Дивочий, А. В., Вахтомин, Ю. Б., Финкель, М. И., & Смирнов, К. В. (2014). Способ прецизионного позиционирования чувствительного элемента фотонного детектора.
Abstract: Изобретение относится к способам, позволяющим производить совмещение фотонных детекторов относительно оптического излучения. Способ прецизионного позиционирования чувствительного элемента фотонного детектора относительно амплитудно-модулированного оптического излучения включает смещение чувствительного элемента фотонного детектора постоянным током с последующей регистрацией электрического сигнала, возникающего на контактах детектора на частоте модуляции излучения. Полученный при этом сигнал используют как параметр, определяющий качество позиционирования. Обеспечивается повышение технико-эксплуатационных характеристик детектора.
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Гольцман, Г. Н., Веревкин, А. А., Гершензон, Е. М., Птицина, Н. Г., Смирнов, К. В., & Чулкова, Г. М. (1995). Исследования процессов неупругой релаксации и примесная спектроскопия-релаксометрия в двумерном электронном газе в полупроводниковых структурах с квантовыми ямами.
Abstract: В гетероструктурах GaAs/AlGaAs впервые прямым методом измерена температурная зависимость вpемени энеpгетической pелаксации двумерного электронного газа te(T) в широком диапазоне температур Т=1,5 – 50 К в квазиравновесных условиях. Для измерений использовался высокочувствительный спектрометр миллиметрового диапазона волн с высоким временным разрешением, который позволял измерять релаксационные времена до 150 пс с погрешностью не более 20%. Верхний предел температуры определялся временным разрешением спектрометра. Исследования проводились на высококачественных образцах с поверхностной концентрацией носителей ns = 4,2 1011 см-2 и подвижностью m = 7 105 см2В-1с-1 (при Т = 4,2К). В квазиравновесных условиях из температурной зависимости tе определен предел подвижности при низких температурах (T<4.2 K), связанный с рассеянием на пьезоакустическом потенциале, получено время неупругой релаксации, связанное с рассеянием на деформационном потенциале (15 K25 K), получено характерное время испускания оптического фонона (tLO>4,5пс), которое существенно превышает время сронтанного излучения оптического фонона (примерно в 30 раз), что связано с большой ролью процессов перепоглащения фононов электронами.При низких температурах проведены измерения tе в условиях сильного разогрева. Полученные значения tе и зависимость tе от температуры электронов Те совпадают с tе(Т) в квазиравновесных условиях при Т=Те. Из полученных значений tе(Те) построена зависимость мощности энергетических потерь от Те, которая хорошо согласуется с литературными данными.Начаты измерения в магнитном поле, которые показывают переспективность использованного нами метода измерений как в области слабых магнитных полей при факторе заполнения >10, так и в области сильных магнитных полей при факторе заполнения >1-2.
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Morozov, D. V., Smirnov, K. V., Smirnov, A. V., Lyakhov, V. A., & Goltsman, G. N. (2005). A millimeter-submillimeter phonon-cooled hot-electron bolometer mixer based on two-dimensional electron gas in an AlGaAs/GaAs heterostructure. Semicond., 39(9), 1082–1086.
Abstract: Experimental results obtained by studying the main characteristics of a millimeter-submillimeter wave mixer based on the hot-electron effect in a two-dimensional electron gas in a AlGaAs/GaAs heterostructure with a phonon-scattering cooling mechanism for charge carriers are reported. The gain bandwidth of the mixer is 4 GHz, the internal conversion losses are 13 dB, and the optimum local-oscillator power is 0.5 μW (for a mixer area of 1 μm2). It is shown that a millimeter-submillimeter-wave receiver with a noise temperature of 1900 K can be developed on the basis of a AlGaAs/GaAs mixer. This mixer also appears to be promising for use in array receiver elements.
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Смирнов, К. В., Чулкова, Г. М., Вахтомин, Ю. Б., Корнеев, А. А., Окунев, О. В., Дивочий, А. В., et al. (2014). Особенности разогрева и релаксации горячих электронов О-754 в тонкопленочных cверхпроводниковых наноструктурах и 2D полупроводниковых гетероструктурах при поглощении излучения инфракрасного и терагерцового диапазонов. МПГУ.
Abstract: В монографии рассмотрены основные особенности эффекта электронного разогрева в тонких сверхпроводниковых пленках и полупроводниковых гетеропереходах, возникающего при поглощении носителями заряда излучений терагерцового и инфракрасного диапазонов.
Значительная часть монографии посвящена представлению современных достижений при использовании указанного эффекта для создания приемных устройств с рекордными характеристиками: терагерцовых гетеродинных и болометрических приемников на основе сверхпроводниковых и полупроводниковых структур; сверхпроводниковых приемников одиночных ИК фотонов. В работе также подробно рассмотрены основы современной сверхпроводниковой тонкопленочной технологии.
Монография может быть полезна студентам старших курсов, аспирантам и начинающим исследователям, работающим в области физики твердого тела, оптики, радиофизики.
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Шангина, Е. Л., Смирнов, К. В., Морозов, Д. В., Ковалюк, В. В., Гольцман, Г. Н., Веревкин, А. А., et al. (2010). Концентрационная зависимость полосы преобразования смесителей субмиллиметрового диапазона на основе наноструктур AlGaAs/GaAs. Изв. РАН Сер. Физ., 74(1), 110–112.
Abstract: Методом субмиллиметровой спектроскопии с высоким временным разрешением при Т = 4.2 К измерена концентрационная зависимость полосы преобразования гетеродинного детектирования гетероструктур AlGaAs/GaAs с двумерным электронным газом. С увеличением концентрации двумерных электронов ns = (1.6–6.6) · 1011см-2 ширина полосы преобразования f3dB уменьшается от 245 до 145 МГц. В исследованной области концентраций наблюдается зависимость f3dB , обусловленная рассеянием электронов на деформационном потенциале акустических фононов и пьезоэлектрическим рассеянием.
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Shangina, E. L., Smirnov, K. V., Morozov, D. V., Kovalyuk, V. V., Gol’tsman, G. N., Verevkin, A. A., et al. (2010). Concentration dependence of the intermediate frequency bandwidth of submillimeter heterodyne AlGaAs/GaAs nanostructures. Bull. Russ. Acad. Sci. Phys., 74(1), 100–102.
Abstract: The concentration dependence of the intermediate frequency bandwidth of heterodyne AlGaAs/GaAs detectors with 2D electron gas is measured using submillimeter spectroscopy with high time resolution at T= 4.2 K. The intermediate frequency bandwidth f3dBfalls from 245 to 145 MHz with increasing concentration of 2D electrons n s = (1.6-6.6) × 10[su11] cm-2. The dependence f3dB ≈ n s – 0.04±is observed in the studied concentration range; this dependence is determined by electron scattering by the deformation potential of acoustic phonons and piezoelectric scattering.
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Verevkin, A., Gershenzon, E. M., Gol'tsman, G. N., Ptitsina, N. G., Chulkova, G. M., Smirnov, K. S., et al. (2002). Direct measurements of energy relaxation times in two-dimensional structures under quasi-equilibrium conditions. In Mater. Sci. Forum (Vol. 384-3, pp. 107–116).
Abstract: A new microwave technique was successfully applied for direct studies of energy relaxation times in two-dimensional AlGaAs/GaAs structures under quasi-equilibrium conditions in the nanosecond and picosecond time scale. We report our results of energy relaxation time measurements in the temperature range 1.6-50 K, in quantum Hall effect regime in magnetic fields up to 4 T.
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Gol’tsman, G. N., & Smirnov, K. V. (2001). Electron-phonon interaction in a two-dimensional electron gas of semiconductor heterostructures at low temperatures. Jetp Lett., 74(9), 474–479.
Abstract: Theoretical and experimental works devoted to studying electron-phonon interaction in the two-dimensional electron gas of semiconductor heterostructures at low temperatures in the case of strong heating in an electric field under quasi-equilibrium conditions and in a quantizing magnetic field perpendicular to the 2D layer are considered.
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Verevkin, A. A., Ptitsina, N. G., Smirnov, K. V., Voronov, B. M., Gol’tsman, G. N., Gershenson, E. M., et al. (1999). Multiple Andreev reflection in hybrid AlGaAs/GaAs structures with superconducting NbN contacts. Semicond., 33(5), 551–554.
Abstract: The conductivity of hybrid microstructures with superconducting contacts made of niobium nitride to a semiconductor with a two-dimensional electron gas in a AlGaAs/GaAs heterostructure has been investigated. Distinctive features of the behavior of the conductivity indicate the presence of multiple Andreev reflection at scattering centers in the normal region near the superconductor-semiconductor boundary.
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Verevkin, A. A., Ptitsina, N. G., Smirnov, K. V., Goltsman, G. N., Gershenson, E. M., & Yngvesson, K. S. (1997). Direct measurements of electron energy relaxation times at an AlGaAs/GaAs heterointerface in the optical phonon scattering range. In Proc. 4-th Int. Semicond. Device Research Symp. (pp. 55–58).
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Verevkin, A. A., Ptitsina, N. G., Smirnov, K. V., Gol’tsman, G. N., Gershenzon, E. M., & Ingvesson, K. S. (1996). Direct measurements of energy relaxation times on an AlGaAs/GaAs heterointerface in the range 4.2–50 K. JETP Lett., 64(5), 404–409.
Abstract: The temperature dependence of the energy relaxation time τe (T) of a two-dimensional electron gas at an AlGaAs/GaAs heterointerface is measured under quasiequilibrium conditions in the region of the transition from scattering by acoustic phonons to scattering with the participation of optical phonons. The temperature interval of constant τe, where scattering by the deformation potential predominates, is determined. In the preceding, low-temperature region, where piezoacoustic and deformation-potential-induced scattering processes coexist, τ e decreases slowly with increasing temperature. Optical phonons start to participate in the scattering processes at T∼25 K (the characteristic phonon lifetime was equal to τLOτ4.5 ps). The energy losses calculated from the τe data in a model with an effective nonequilibrium electron temperature agree with the published data obtained under strong heating conditions.
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Verevkin, A. A., Ptitsina, N. G., Chulcova, G. M., Gol'tsman, G. N., Gershenzon, E. M., & Yngvesson, K. S. (1996). Direct measurements of energy relaxation time of electrons in AlGaAs/GaAs heterostructures under quasi-equilibrium conditions. Surface Science, 361-362, 569–573.
Abstract: For the first time, results are presented of a direct measurement of the energy relaxation time τε of 2D electrons in an AlGaAs/GaAs heterojunction at T = 1 and 5–20 K. A weak temperature dependence of τε for the T > 4K range and a linear temperature dependence of the reciprocal of τε for T < 4K have been observed. The linear dependence τε−1 ≈ T in the Bloch-Gruneisen regime is direct evidence of the predominance of the piezo-electric mechanism of electron-phonon interaction in non-elastic electron scattering processes. The values of τε in this regime are in very good agreement with the results of the Karpus theory. At higher temperatures, where the deformation-potential scattering becomes noticeable, a substantial disagreement between the experimental data and the theoretical results is observed.
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Verevkin, A. A., Ptitsina, N. G., Chulcova, G. M., Gol'Tsman, G. N., Gershenzon, E. M., & Yngvesson, K. S. (1996). Determination of the limiting mobility of a two-dimensional electron gas in AlxGa1-xAs/GaAs heterostructures and direct measurement of the energy relaxation time. Phys. Rev. B Condens. Matter., 53(12), R7592–R7595.
Abstract: We present results for a method to measure directly the energy relaxation time (τe) for electrons in a single AlxGa1−xAs/GaAs heterojunction; measurements were performed from 1.6 to 15 K under quasiequilibrium conditions. We find τeαT−1 below 4 K, and τe independent of T above 4 K. We have also measured the energy-loss rate, ⟨Q⟩, by the Shubnikov-de Haas technique, and find ⟨Q⟩α(T3e−T3) for T<~4.2 K; Te is the electron temperature. The values and temperature dependence of τe and ⟨Q⟩ for T<4 K agree with calculations based on piezoelectric and deformation potential acoustic phonon scattering. At 4.2 K, we can also estimate the momentum relaxation time, τm, from our measured τe. This leads to a preliminary estimate of the phonon-limited mobility at 4.2 K of μ=3×107 cm2/Vs (ns=4.2×1011 cm−2), which agrees well with published numerical calculations, as well as with an earlier indirect estimate based on measurements on a sample with much higher mobility.
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Verevkin, A. I., Ptitsina, N. G., Chulkova, G. M., Gol'tsman, G. N., Gershenzon, E. M., & Yngvesson, K. S. (1995). Electron energy relaxation in a 2D channel in AlGaAs-GaAs heterostructures under quasiequilibrium conditions at low temperatures. JETP Lett., 61(7), 591–595.
Abstract: The energy relaxation time of 2D electrons, Te, has been measured under quasiequilibrium conditions in AlGaAs—GaAs heterojunctions over the temperature range T= 1.5—20 K. At T> 4 K, Te depends only weakly on the temperature, while at T< 4 K 7;'(T) there is a dependence fr; lNT. A linear dependence 7: 1 (T) in the Bloch—-Grfineisen temperature region (T< 5 K) is unambiguous evidence that a piezoacoustic mechanism of an electron—phonon interaction is predominant in the inelastic scattering of electrons. The values of T6 in this temperature range agree very accurately with theoretical results reported by Karpus [Sov. Phys. Semicond. 22 (1988)]. At higher temperatures, where scat—tering by deformation acoustic phonons becomes substantial, there is a significant discrepancy between the experimental and theoretical re-sults.
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Гольцман, Г. Н., & Смирнов, К. В. (2001). По итогам проектов российского фонда фундаментальных исследований. Проект РФФИ # 98-02-16897 Электрон-фононное взаимодействие в двумерном электронном газе полупроводниковых гетероструктур при низких температурах. Письма в ЖЭТФ, 74(9), 532–538.
Abstract: Рассмотрены теоретические и экспериментальные работы, посвященные изучению электрон-фононного взаимодействия в двумерном электронном газе полупроводниковых гетероструктур при низких температурах в случае сильного разогрева в электрическом поле, в квазиравновесных условиях и в квантующем магнитном поле, перпендикулярном 2D слою.
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Шангина, Е. Л., Смирнов, К. В., Морозов, Д. В., Ковалюк, В. В., Гольцман, Г. Н., Веревкин, А. А., et al. (2010). Полоса и потери преобразования полупроводникового смесителя с фононным каналом охлаждения двумерных электронов. Физика и техника полупроводников, 44(11), 1475–1478.
Abstract: Методом субмиллиметровой спектроскопии с высоким временным разрешением измерены температурная и концентрационная зависимости полосы преобразования смесителей терагерцового диапазона AlGaAs/GaAs на разогреве двумерных электронов с фононным каналом их охлаждения. Полоса преобразования на уровне 3 дБ (f3 dB) при 4.2 K при изменении концентрации ns варьируется в пределах 150-250 МГц в соответствии со степенным законом f3 dB propto ns-0.5, что соответствует доминирующему механизму рассеяния на пьезоэлектрических фононах. Минимальное значение коэффициента потерь преобразования полупроводникового смесителя достигается в структурах с высокой подвижностью носителей mu>3·105 см2/В·с при 4.2 K.
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Shangina, E. L., Smirnov, K. V., Morozov, D. V., Kovalyuk, V. V., Gol’tsman, G. N., Verevkin, A. A., et al. (2010). Frequency bandwidth and conversion loss of a semiconductor heterodyne receiver with phonon cooling of two-dimensional electrons. Semicond., 44(11), 1427–1429.
Abstract: The temperature and concentration dependences of the frequency bandwidth of terahertz heterodyne AlGaAs/GaAs detectors based on hot electron phenomena with phonon cooling of two-dimensional electrons have been measured by submillimeter spectroscopy with a high time resolution. At a temperature of 4.2 K, the frequency bandwidth at a level of 3 dB (f 3 dB) is varied from 150 to 250 MHz with a change in the concentration n s according to the power law f 3dB ∝ n −0.5 s due to the dominant contribution of piezoelectric phonon scattering. The minimum conversion loss of the semiconductor heterodyne detector is obtained in structures with a high carrier mobility (μ > 3 × 105 cm2 V−1 s−1 at 4.2 K).
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Смирнов, К. В. (2003). AlGaAs/GaAs смеситель на эффекте разогрева двумерных электронов для тепловизора субмиллиметрового диапазона. In Тезисы докладов VI Российской конференции по физике полупроводников (181).
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Смирнов, К. В. (2000). Энергетическая релаксация электронов в 2D-канале гетеропереходов GAAS/ALGAAS и транспортные процессы в структурах полупроводник-сверхпроводник на их основе. Ph.D. thesis, , .
Abstract: Диссертация посвящена изучению электрон-фононного взаимодействия в двумерном электронном газе, образующемся на границе раздела полупроводников AlGaAs и GaAs, а также созданию на основе гетероперехода GaAs/AlGaAs и сверхпроводника NbN гибридных структур сверхпроводник-полупроводник-сверхпроводник и изучению их электрофизических свойств.
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Чулкова, Г. М., Корнеев, А. А., Смирнов, К. В., & Окунев, О. В. (2012). Энергетическая релаксация в примесных металлах, двумерном электронном газе в AlGaAs-GaAs, сверхпроводниковых пленках NbN и детекторы субмиллиметрового и ик излучения на их основе. Прометей, МПГУ.
Abstract: Монография посвящена обзору исследований влияния эффектов электронного беспорядка на электронное взаимодействие в металлах, сверхпроводниках, полупроводниках, а также в различных низкоразмерных структурах. Актуальность поднятых в монографии вопросов определяется интенсивным развитием нанотехнологий, созданием новых наноструктурированных материалов и уникальных наноэлементов для электроники и фотоники. Упругое электронное рассеяние на границах наноструктур качественно меняет взаимодействие электронов с фонолами, что, безусловно, должно учитываться при проектировании соответствующей элементной базы. Прикладная часть работы посвящена контролируемой модификации электронных процессов для оптимизации новых наносенсоров на основе электронного разогрева в сверхпроводниковых и полупроводниковых структурах. Монография предназначена для студентов старших курсов, аспирантов и начинающих следователей, работающих в области сверхпроводниковой наноэлектроники.
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Smirnov, K. V., Ptitsina, N. G., Vakhtomin, Y. B., Verevkin, A. A., Gol’tsman, G. N., & Gershenzon, E. M. (2000). Energy relaxation of two-dimensional electrons in the quantum Hall effect regime. JETP Lett., 71(1), 31–34.
Abstract: The mm-wave spectroscopy with high temporal resolution is used to measure the energy relaxation times τe of 2D electrons in GaAs/AlGaAs heterostructures in magnetic fields B=0–4 T under quasi-equilibrium conditions at T=4.2 K. With increasing B, a considerable increase in τe from 0.9 to 25 ns is observed. For high B and low values of the filling factor ν, the energy relaxation rate τ −1e oscillates. The depth of these oscillations and the positions of maxima depend on the filling factor ν. For ν>5, the relaxation rate τ −1e is maximum when the Fermi level lies in the region of the localized states between the Landau levels. For lower values of ν, the relaxation rate is maximum at half-integer values of τ −1e when the Fermi level is coincident with the Landau level. The characteristic features of the dependence τ −1e (B) are explained by different contributions of the intralevel and interlevel electron-phonon transitions to the process of the energy relaxation of 2D electrons.
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Anosov, A. A., Barabanenkov, Y. N., Kazanskii, A. S., Less, Y. A., & Sharakshane, A. S. (2009). The inverse problem of acoustothermography with correlation reception of thermal acoustic radiation. Acoust. Phys., 55(1), 114–119.
Abstract: For the one-dimensional inverse problem of acoustothermography with correlation reception of thermal acoustic radiation, an integral equation is presented and experimentally verified. A method of solving the inverse problem is proposed. The method is based on combining the correlation functions of thermal acoustic radiation that were obtained for different distances between the receivers.
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Anosov, A. A., Nemchenko, O. Y., Less, Y. A., Kazanskii, A. S., & Mansfel'd, A. D. (2015). Possibilities of acoustic thermometry for controlling targeted drug delivery. Acoust. Phys., 61(4), 488–493.
Abstract: Model acoustic thermometry experiments were conducted during heating of an aqueous liposome suspension. Heating was done to achieve the liposome phase transition temperature. At the moment of the phase transition, the thermal acoustic signal achieved a maximum and decreased, despite continued heating. During subsequent cooling of the suspension, when lipids again passed through the phase transition point, the thermal acoustic signal again increased, despite a reduction in temperature. This effect is related to an increase in ultrasound absorption by the liposome suspension at the moment of the lipid phase transition. The result shows that acoustic thermography can be used to control targeted delivery of drugs mixed in thermally sensitive liposomes, the integrity of which is violated during heating to the phase transition temperature.
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Ovchinnikov, O. V., Perepelitsa, A. S., Smirnov, M. S., Latyshev, A. N., Grevtseva, I. G., Vasiliev, R. B., et al. (2020). Luminescence of colloidal Ag2S/ZnS core/shell quantum dots capped with thioglycolic acid. J. Luminescence, 220, 117008 (1 to 7).
Abstract: The features of IR luminescence of colloidal AgS QDs passivated with thioglycolic acid (AgS/TGA) under the formation of AgS/ZnS/TGA core/shell QDs are considered. A 4.5-fold increase in the quantum yield of recombination IR luminescence within the band with a peak at 960 nm (1.29 eV), full width at half maximum of 250 nm (0.34 eV), and the Stokes shift with respect to the exciton absorption of 0.6 eV was found. The increase in the IR luminescence intensity of AgS/ZnS/TGA QDs is accompanied by an increase in the average luminescence lifetime from 2.9 ns to 14.3 ns, which is explained as “healing” of surface trap states during the formation of the ZnS shell. For the first time, the enhancement of the luminescence intensity photodegradation (hereinafter referred to as fatigue) was found during the formation of the AgS/ZnS/TGA core/shell QDs. The luminescence fatigue is irreversible. We conclude that the initial stage of photolysis of the AgS core QDs under laser irradiation plays a key role. Low-atomic photolytic clusters of silver formed on the AgS core QDs act as luminescence quenching centers and do not reveal structural transformations into AgS, provided that the clusters are not in contact with TGA.
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Tretyakov, I., Svyatodukh, S., Chumakova, A., Perepelitsa, A., Kaurova, N., Shurakov, A., et al. (2019). Room temperature silicon detector for IR range coated with Ag2S quantum dots. In IRMMW-THz.
Abstract: A silicon has been the chief technological semiconducting material of modern microelectronics and has had a strong influence on all aspects of society. Applications of Si-based optoelectronic devices are limited to the visible and near infrared ranges. The expansion of the Si absorption to shorter wavelengths of the infrared range is of considerable interest to optoelectronic applications. By creating impurity states in Si it is possible to cause sub-band gap photon absorption. Here, we present an elegant and effective technology of extending the photoresponse of towards the IR range. Our approach is based on the use of Ag 2 S quantum dots (QDs) planted on the surface of Si. The specific sensitivity of the Ag 2 S/Si heterostructure is 10 11 cm√HzW -1 at 1.55μm. Our findings open a path towards the future study and development of Si detectors for technological applications.
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Chulcova, G. M., Ptitsina, N. G., Gershenzon, E. M., Gershenzon, M. E., & Sergeev, A. V. (1996). Effect of the interference between electron-phonon and electron-impurity (boundary) scattering on resistivity Nb, Al, Be films. In Czech J. Phys. (Vol. 46, pp. 2489–2490).
Abstract: The temperature dependence of the resistivity of thin Nb, Al, Be films has been studied over a wide temperature range 4-300 K. We have found that the temperature-dependent correction to the residual resistivity is well described by the sum of the Bloch-Grüneisen term and the term originating from the interference between electron-phonon and electron-impurity scattering. Study of the transport interference phenomena allows to determine electron-phonon coupling in disordered metals. The interference term is proportional to T2 and also to the residual resistivity and dominates over the Bloch-Grüneisen term at low temperatures (T<40 K).
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Maslennikov, S. N., Morozov, D. V., Ozhegov, R. V., Smirnov, K. V., Okunev, O. V., & Gol’tsman, G. N. (2004). Imaging system for submillimeter wave range based on AlGaAs/GaAs hot electron bolometer mixers. In Proc. 5-th MSMW (Vol. 2, pp. 558–560).
Abstract: Electromagnetic radiation of the submillimeter (SMM) range is dispersed and absorbed significantly less than infrared (IR) radiation when passing through different objects. That is the reason for the development of an SMM imaging system. In this paper, we discuss the design of an SMM heterodyne imager, based on a matrix of AlGaAs/GaAs heterostructure hot electron bolometer mixers (HEB) with relatively high (about 77 K) operating temperature. The predicted double side band (DSB) noise temperature is about 1000 K and optimal local oscillator (LO) power is about 1 /spl mu/W for such mixers, which seems to be quite prospective for an SMM heterodyne imager.
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Shangina, E. L., Smirnov, K. V., Morozov, D. V., Kovalyuk, V. V., Goltsman, G. N., Verevkin, A. A., et al. (2011). Concentration dependence of energy relaxation time in AlGaAs/GaAs heterojunctions: direct measurements. Semicond. Sci. Technol., 26(2), 025013.
Abstract: We present measurements of the energy relaxation time, τε, of electrons in a single heterojunction in a quasi-equilibrium state using microwave time-resolved spectroscopy at 4.2 K. We find the relaxation time has a power-law dependence on the carrier density of the two-dimensional electron gas, τε∝nγs with γ = 0.40 ± 0.02 for values of the carrier density, ns, from 1.6 × 1011 to 6.6 × 1011cm−2. The results are in good agreement with predictions taking into account the scattering of the carriers by both piezoelectric and deformation potential acoustic phonons. We compare these results with indirect measurements of the energy relaxation time from energy loss measurements involving Joule heating of the electron gas.
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Schwaab, G. W., Hübers, H. - W., Schubert, J., Erichsen, P., Gol'tsman, G., Semenov, A., et al. (1999). A high resolution spectrometer for the investigation of molecular structures in the THZ range. In Proc. 10th Int. Symp. Space Terahertz Technol. (pp. 530–538).
Abstract: A status report on the design study of a novel tunable far-infrared (TuFTR) spectrometer for the investigation of the structure of weakly bound molecular complexes is given. The goal is a sensitive TuFIR spectrometer with full frequency coverage from 1-6 THz. To hit the goal, advanced sources (e.g. p-Ge lasers) and detectors (e.g. superconducting hot electron bolometric (HEB) mixers) shall be employed to extend the technique of cavity ringdown spectroscopy, that is currently used at optical and infrared frequencies to the FIR spectral range. Critical for such a system are high-Q resonators that still allow good optical coupling, and wideband antireflection coatings to increase detector sensitivity and decrease optical path losses. 2 nd order effective media theory and an iterative multilayer algorithm have been employed to design wideband antireflection coatings for dielectrics with large dielectric constants like Ge or Si. Taking into account 6 layers, for Si bandwidths of 100% of the center frequency could be obtained with power reflectivities below 1% for both polarizations simultaneously. Wideband dielectric mirrors including absorption losses were also studied yielding a bandwidth of about 50% with reflectivities larger than 99.5%.
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Kardakova, A., Shishkin, A., Semenov, A., Goltsman, G. N., Ryabchun, S., Klapwijk, T. M., et al. (2016). Relaxation of the resistive superconducting state in boron-doped diamond films. Phys. Rev. B, 93(6), 064506.
Abstract: We report a study of the relaxation time of the restoration of the resistive superconducting state in single crystalline boron-doped diamond using amplitude-modulated absorption of (sub-)THz radiation (AMAR). The films grown on an insulating diamond substrate have a low carrier density of about 2.5×1021cm−3 and a critical temperature of about 2K. By changing the modulation frequency we find a high-frequency rolloff which we associate with the characteristic time of energy relaxation between the electron and the phonon systems or the relaxation time for nonequilibrium superconductivity. Our main result is that the electron-phonon scattering time varies clearly as T−2, over the accessible temperature range of 1.7 to 2.2 K. In addition, we find, upon approaching the critical temperature Tc, evidence for an increasing relaxation time on both sides of Tc.
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Zubkova, E., An, P., Kovalyuk, V., Korneev, A., Ferrari, S., Pernice, W., et al. (2018). Optimization of contra-directional coupler based on silicon nitride Bragg rib waveguide. In J. Phys.: Conf. Ser. (Vol. 1124, 051048).
Abstract: We report on the development and fabrication of a contra-directional coupler based on the Bragg waveguide on Si3N4 platform. Transmitted and reflected by the contra-directional coupler spectra were measured. The reflected spectra exactly matches the one notched by the main channel of the coupler. Losses are about 3dB, coupling to the directing branch of the coupler is practically lossless. FWHM of the transmitted (reflected) spectra is 3.46 nm.
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Zubkova, E., An, P., Kovalyuk, V., Korneev, A., & Goltsman, G. (2017). Integrated Bragg waveguides as an efficient optical notch filter on silicon nitride platform. In Proc. SPBOPEN (pp. 449–450).
Abstract: We modeled and fabricated integrated optical Bragg waveguides on a silicon nitride (Si3N4) platform. Transmission spectra of the integrated notch filter has been measured and attenuation at the desired wavelength of 1550 nm down to -43 dB was observed.
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Komrakova, S., Javadzade, J., Vorobyov, V., Bolshedvorskii, S., Soshenko, V., Akimov, A., et al. (2019). CMOS compatible nanoantenna-nanodiamond integration. In J. Phys.: Conf. Ser. (Vol. 1410, 012180).
Abstract: Here we demonstrate CMOS compatible method to deterministically produce nanoantenna with nanodiamonds systems on example of bull-eye antenna on top of on hyperbolic metamaterials. We study the statistics of the placement of nanodiamonds and measure the fluorescence lifetime and the second-order correlation function of NV-centers inside nanodiamonds.
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Гершензон, Е. М., Гольцман, Г. Н., Елантьев, А. И., Кагане, М. Л., Мултановский, В. В., & Птицина, Н. Г. (1983). Применение субмиллиметровой ЛОВ спектроскопии для определения химической природы и концентрации примесей в чистых полупроводниках. Физика и техника полупроводников, 17(8), 1430–1437.
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Gershenson, E. M., Gol'tsman, G. N., Elant'ev, A. I., Kagane, M. L., Multanovskii, V. V., & Ptitsina, N. G. (1983). Use of submillimeter backward-wave tube spectroscopy in determination of the chemical nature and concentration of residual impurities in pure semiconductors. Sov. Phys. Semicond., 17(8), 908–913.
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Gershenzon, E. M., Gol'tsman, G. N., & Semenov, A. D. (1983). Submillimeter backward wave tube spectrometer for measuring superconducting film transmission. Pribory i Tekhnika Eksperimenta, 26(5), 134–137.
Abstract: A spectrometer employing six backward wave tubes is described. It is intended for investigation of superconductors in the 0.2-3 mm range of wave lengths. During the measurement of the transmission spectrum it is possible to determine the energy gap for superconduct1ng films 50 to 4000 A thick. The transmission factor can vary from 10-1 to 10-9. Spectrum of relation of film transmission factors in superconducting and normal states is measured for determining the energy gap 2 Δ. The transmission spectrum obtained by means of a computer for vanadium film 300 A thick is given as an example. The energy gap 2 Δ = 1.4 MeV
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Aksaev, E. E., Gershenzon, E. M., Gol'tsman, G. N., Mirskij, G. I., & Semenov, A. D. (1991). Submillimetric spectrometer-relaxometer based on backward-wave tubes with picosecond time resolution. Pribory i Tekhnika Eksperimenta, 34(2), 125–131.
Abstract: The high-sensitive automatic spectrometer-relaxometer based on backward-wave tubes in the range of 4÷0.25 mm was described permitting to study the response kinetics of sample under investigation in any point of this range with the resolution time of 10-11 s. The relaxation measurements were conducted using oscillation beats of two adequate tubes, the frequency of one of them was fixed, while that of the other one was changeable. The amplitude-frequency characteristic of the response under the conditions of synchronous reception was recorded at beat frequency variation from 107 to 1010 Hz. The high sensitivity was reached by decreasing the device recording band down to 100 Hz in the whole measuring range.
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Gershenzon, E. M., Gol'tsman, G. N., & Mirskii, G. I. (1987). Submillimeter backward-wave-tube spectrometer-relaxometer. Pribory i Tekhnika Eksperimenta, 30(4), 131–137.
Abstract: A backward-wave-tube (BWT) spectrometer-relaxometer is described that is designed for study of the relaxation characteristics of photoconductors in the wavelength range of 2-0.25 mm – in particular, to measure the relaxation times of the submillimeter photoconductivity of germanium in the range of 10[sup:-4]-10[sup:-9] sec and to determine from these data the concentration of compensating impurities of from 10[sup:10] to 10[sup:14] cm[sup:-3]. The instrument uses the beats of the oscillations of two BWTs and records the amplitude-frequency response of the specimen with variation of the beat frequency from 10[sup:4] to 10[sup:8] Hz with accumulation of the desired signal for less than or equal to1 sec by means of a quadrature synchronous detector. The beat frequency is stabilized and the quadrature voltages of the synchronous detector are formed by means of phase-locked loops.
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Iomdina, E. N., Seliverstov, S., Sianosyan, A., Teplyakova, K., Rusova, A., & Goltsman, G. (2016). The prospects of using the radiation for the assessment of corneal and scleral hydration. In Acta Ophthalmol. (Vol. 94).
Abstract: Purpose
An adequate water balance (hydration extent) is one of the basic factors of normal eye function, including its external shells – the cornea and the sclera. THz systems creating images in reflected beams are likely to become ideal instruments of noninvasive testing of corneal and scleral hydration degree as THz radiation is highly sensitive to water content. The paper aims at studying the transmittance and reflectance spectra of the cornea and the sclera of rabbit and human eyes, as well as those of the whole rabbit eye, in the frequency range of 0.13–0.32 THz.
Methods
The experiments were carried out on 3 corneas and 3 rabbit scleras, 2 whole rabbit eyes, and 3 human healthy adult scleras using a specially developed THz system based on reliable and easy‐to‐use continuous wave sources: a backward‐wave oscillator and an avalanche transit‐time diode.
Results
The transmittance spectra of the cornea and the sclera and the dependence of the reflection coefficient of these tissues in THz range on water percentage content were determined. Comparison of the rabbit cornea hydrated from 73.2% to 76.3% concentration by mass demonstrated an approximately linear relationship between THz reflectivity and water concentration. The decrease of free water concentration by 1% leads to a drop of the reflectance coefficient by 13%. The parameters studied displayed noticeable differences between the sclera and the cornea of rabbits and between rabbit sclera and human sclera.
Conclusions
Preliminary results demonstrate that the proposed technique, based on continuous THz radiation, may be used to create a device for noninvasive testing of corneal and scleral hydration, which has good potential of wide‐scale practical application.
The work was supported by the Russian Foundation of Basic Research (grant No.15‐29‐03843)
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Gol’tsman, G. N. (1994). Terahertz technology in Russia. In 24th European Microwave Conf. (Vol. 1, pp. 113–121).
Abstract: The presentation consider the parameters and operating peculiarities of unique microwave generators of the terahertz range which have been created in Russia – the backward wave oscillators – as well as certain devices based on these generators, such as high resolution. spectrometers and time-resolving spectrometers with picosecond temporal resolution. Most resent BWO-based studies are illustrated by a project devoted to superconductive hot-electron. bolometers which are of great independent value for the terahertz technology as high-sensitive picosecond detectors and low noise broad-band mixers.
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Iomdina, E. N., Goltsman, G. N., Seliverstov, S. V., Sianosyan, A. A., Teplyakova, K. O., & Rusova, A. A. (2016). Study of transmittance and reflectance spectra of the cornea and the sclera in the THz frequency range. J. Biomed. Opt., 21(9), 97002 (1 to 5).
Abstract: An adequate water balance (hydration extent) is one of the basic factors of normal eye function, including its external shells: the cornea and the sclera. Adequate control of corneal and scleral hydration is very important for early diagnosis of a variety of eye diseases, stating indications for and contraindications against keratorefractive surgeries and the choice of contact lens correction solutions. THz systems of creating images in reflected beams are likely to become ideal instruments of noninvasive control of corneal and scleral hydration degrees. This paper reports on the results of a study involving transmittance and reflectance spectra for the cornea and the sclera of rabbit and human eyes, as well as those of the rabbit eye, in the frequency range of 0.13 to 0.32 THz. The dependence of the reflectance coefficient of these tissues on water mass percentage content was determined. The experiments were performed on three corneas, three rabbit scleras, two rabbit eyes, and three human scleras. The preliminary results demonstrate that the proposed technique, based on the use of a continuous THz radiation, may be utilized to create a device for noninvasive control of corneal and scleral hydration, which has clear potential of broad practical application.
Keywords: BWO, IMPATT diode, Schottky diode, medicine, animals, cornea, physiology, humans, rabbits, sclera diagnostic imaging, physiology
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Iomdina, E. N., Seliverstov, S. V., Sianosyan, A. A., Teplyakova, K. O., Rusova, A. A., & Goltsman, G. N. (2018). Terahertz scanning for evaluation of corneal and scleral hydration. STM, 10(4), 143–149.
Abstract: The aim of the investigation was to study the prospects of using continuous THz scanning of the cornea and the sclera to determine water concentration in these tissues and on the basis of the obtained data to develop the experimental installation for monitoring corneal and scleral hydration degree.Materials and Methods. To evaluate corneal and scleral transmittance and reflectance spectra in the THz range, the developed experimental installations were used to study 3 rabbit corneas and 3 scleras, 2 whole rabbit eyes, and 3 human scleras. Besides, two rabbit eyes were studied in vivo prior to keratorefractive surgery as well as 10 and 21 days following the surgery (LASIK).Results. There have been created novel experimental installations enabling in vitro evaluation of frequency dependence of corneal and scleral transmittance coefficients and reflectance coefficients on water percentage in the THz range. Decrease in corneal water content by 1% was found to lead to reliably established decrease in the reflected signal by 13%. The reflectance spectrum of the whole rabbit eye was measured in the range of 0.13–0.32 THz. The study revealed the differences between the indices of rabbit cornea and sclera, as well as rabbit and human sclera. There was developed a laboratory model of the installation for in vivo evaluation of corneal and scleral hydration using THz radiation.Conclusion. The preliminary findings show that the proposed technique based on the use of continuous THz radiation can be employed to create a device for noninvasive control of corneal and scleral hydration.
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Fedorov, G., Gayduchenko, I., Titova, N., Gazaliev, A., Moskotin, M., Kaurova, N., et al. (2018). Carbon nanotube based schottky diodes as uncooled terahertz radiation detectors. Phys. Status Solidi B, 255(1), 1700227 (1 to 6).
Abstract: Despite the intensive development of the terahertz technologies in the last decade, there is still a shortage of efficient room‐temperature radiation detectors. Carbon nanotubes (CNTs) are considered as a very promising material possessing many of the features peculiar for graphene (suppression of backscattering, high mobility, etc.) combined with a bandgap in the carrier spectrum. In this paper, we investigate the possibility to incorporate individual CNTs into devices that are similar to Schottky diodes. The latter is currently used to detect radiation with a frequency up to 50 GHz. We report results obtained with semiconducting (bandgap of about 0.5 eV) and quasi‐metallic (bandgap of few meV) single‐walled carbon nanotubes (SWNTs). Semiconducting CNTs show better performance up to 300 GHz with responsivity up to 100 V W−1, while quasi‐metallic CNTs are shown to operate up to 2.5 THz.
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Khasminskaya, S., Pyatkov, F., Słowik, K., Ferrari, S., Kahl, O., Kovalyuk, V., et al. (2016). Fully integrated quantum photonic circuit with an electrically driven light source. Nat. Photon., 10(11), 727–732.
Abstract: Photonic quantum technologies allow quantum phenomena to be exploited in applications such as quantum cryptography, quantum simulation and quantum computation. A key requirement for practical devices is the scalable integration of single-photon sources, detectors and linear optical elements on a common platform. Nanophotonic circuits enable the realization of complex linear optical systems, while non-classical light can be measured with waveguide-integrated detectors. However, reproducible single-photon sources with high brightness and compatibility with photonic devices remain elusive for fully integrated systems. Here, we report the observation of antibunching in the light emitted from an electrically driven carbon nanotube embedded within a photonic quantum circuit. Non-classical light generated on chip is recorded under cryogenic conditions with waveguide-integrated superconducting single-photon detectors, without requiring optical filtering. Because exclusively scalable fabrication and deposition methods are used, our results establish carbon nanotubes as promising nanoscale single-photon emitters for hybrid quantum photonic devices.
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Pyatkov, F., Khasminskaya, S., Fütterling, V., Fechner, R., Słowik, K., Ferrari, S., et al. (2016). Carbon nanotubes as exceptional electrically driven on-chip light sources. 2physics.com/2016/10. Retrieved May 15, 2024, from http://www.2physics.com/2016/10/carbon-nanotubes-as-exceptional.html
Abstract: Carbon nanotubes (CNTs) belong to the most exciting objects of the nanoworld. Typically, around 1 nm in diameter and several microns long, these cylindrically shaped carbon-based structures exhibit a number of exceptional mechanical, electrical and optical characteristics [1]. In particular, they are promising ultra-small light sources for the next generation of optoelectronic devices, where electrical components are interconnected with photonic circuits.
Few years ago, we demonstrated that electically driven CNTs can serve as waveguide-integrated light sources [2]. Progress in the field of nanotube sorting, dielectrophoretical site-selective deposition and efficient light coupling into underlying substrate has made CNTs suitable for wafer-scale fabrication of active hybrid nanophotonic devices [2,3].
Recently we presented a nanotube-based waveguide integrated light emitters with tailored, exceptionally narrow emission-linewidths and short response times [4]. This allows conversion of electrical signals into well-defined optical signals directly within an optical waveguide, as required for future on-chip optical communication. Schematics and realization of this device is shown in Figure 1. The devices were manufactured by etching a photonic crystal waveguide into a dielectric layer following electron beam lithography. Photonic crystals are nanostructures that are also used by butterflies to give the impression of color on their wings. The same principle has been used in this study to select the color of light emitted by the CNT. The precise dimensions of the structure were numerically simulated to tailor the properties of the final device. Metallic contacts in the vicinity to the waveguide were fabricated to provide electrical access to CNT emitters. Finally, CNTs, sorted by structural and electronic properties, were deposited from a solution across the waveguide using dielectrophoresis, which is an electric-field-assisted deposition technique.
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