Gerecht, E., Musante, C. F., Zhuang, Y., Yngvesson, K. S., Gol’tsman, G. N., Voronov, B. M., et al. (1999). NbN hot electron bolometric mixerss—a new technology for low-noise THz receivers. IEEE Trans. Appl. Supercond., 47(12), 2519–2527.
Abstract: New advances in hot electron bolometer (HEB) mixers have recently resulted in record-low receiver noise temperatures at terahertz frequencies. We have developed quasi-optically coupled NbN HEB mixers and measured noise temperatures up to 2.24 THz, as described in this paper. We project the anticipated future performance of such receivers to have even lower noise temperature and local-oscillator power requirement as well as wider gain and noise bandwidths. We introduce a proposal for integrated focal plane arrays of HEB mixers that will further increase the detection speed of terahertz systems.
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Zorin, M., Gol'tsman, G. N., Karasik, B. S., Elantev, A. I., Gershenzon, E. M., Lindgren, M., et al. (1995). Optical mixing in thin YBa2Cu3O7-x films. IEEE Trans. Appl. Supercond., 5(2), 2431–2434.
Abstract: High quality, j/sub c/ (77 K)>10/sup 6/ A/cm/sup 2/, epitaxial YBa2Cu3O7-x films of 50 nm thickness were patterned into ten parallel 1 /spl mu/m wide strips. The film structure was coupled to a single-mode fiber. Mixer response was obtained at 0.78 /spl mu/m using laser frequency modulation and an optical delay line. Using two semiconductor lasers at 1.55 /spl mu/m wavelength the beating signal was used to measure the photoresponse up to 18 GHz. Nonequilibrium photoresponse in the resistive state of the superconductor was observed. Bolometric response dominates up to 3 GHz, after which the nonequilibrium response is constant up to the frequency limit of our registration system. Using an electron heating model the influence of different thermal processes on the conversion loss has been analyzed. Ways of increasing the sensitivity are also discussed.
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Gershenzon, E. M., Gol'tsman, G. N., Dzardanov, A. L., Elant'ev, A. I., Zorin, M. A., Markin, A. G., et al. (1992). S-N switching of niobium and YBCO films: limit time and perspective of fast key element creation. Sverkhprovodimost': Fizika, Khimiya, Tekhnika, 5(12), 2386–2402.
Abstract: A study was made on processes of switching of thin niobium film strips between superconducting and normal states under the effect of optical radiation pulse and voltage step. The results are described satisfactorily by the model of spatial homogeneous electron heating. It is shown that limiting switching times can be equal to several shares of nanosecond at 4.2 K. Preliminary results for YBa2Cu3O-7-x films are presented. Prospects and advantages of creation of ducting structures of narrow streps, are discussed.
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Blagosklonskaya, L. E., Gershenzon, E. M., Gol'tsman, G. N., & Elant'ev, A. I. (1977). Effect of a high magnetic field on the spectrum of donors in InSb. Fizika i Tekhnika Poluprovodnikov, 11(12), 2373–2375.
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Meledin, D. V., Marrone, D. P., Tong, C. - Y. E., Gibson, H., Blundell, R., Paine, S. N., et al. (2004). A 1-THz superconducting hot-electron-bolometer receiver for astronomical observations. IEEE Trans. Microwave Theory Techn., 52(10), 2338–2343.
Abstract: In this paper, we describe a superconducting hot-electron-bolometer mixer receiver developed to operate in atmospheric windows between 800-1300 GHz. The receiver uses a waveguide mixer element made of 3-4-nm-thick NbN film deposited over crystalline quartz. This mixer yields double-sideband receiver noise temperatures of 1000 K at around 1.0 THz, and 1600 K at 1.26 THz, at an IF of 3.0 GHz. The receiver was successfully tested in the laboratory using a gas cell as a spectral line test source. It is now in use on the Smithsonian Astrophysical Observatory terahertz test telescope in northern Chile.
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Karasik, B. S., Il'in, K. S., Pechen, E. V., & Krasnosvobodtsev, S. I. (1996). Diffusion cooling mechanism in a hot-electron NbC microbolometer mixer. Appl. Phys. Lett., 68(16), 2285–2287.
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Karasik, B. S., Gol'tsman, G. N., Voronov, B. M., Svechnikov, S. I., Gershenzon, E. M., Ekstrom, H., et al. (1995). Hot electron quasioptical NbN superconducting mixer. IEEE Trans. Appl. Supercond., 5(2), 2232–2235.
Abstract: Hot electron superconductor mixer devices made of thin NbN films on SiO/sub 2/-Si/sub 3/N/sub 4/-Si membrane have been fabricated for 300-350 GHz operation. The device consists of 5-10 parallel strips each 5 /spl mu/m long by 1 /spl mu/m wide which are coupled to a tapered slot-line antenna. The I-V characteristics and position of optimum bias point were studied in the temperature range 4.5-8 K. The performance of the mixer at higher temperatures is closer to that predicted by theory for uniform electron heating. The intermediate frequency bandwidth versus bias has also been investigated. At the operating temperature 4.2 K a bandwidth as wide as 0.8 GHz has been measured for a mixer made of 6 nm thick film. The bandwidth tends to increase with operating temperature. The performance of the NbN mixer is expected to be better for higher frequencies where the absorption of radiation should be more uniform.
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Gershenzon, E. M., Gol'tsman, G. N., Dzardanov, A. L., & Kuznetsov, E. A. (1992). Superconducting UHF-limiter based on electron heating up. Sverkhprovodimost': Fizika, Khimiya, Tekhnika, 5(11), 2164–2170.
Abstract: The results of experimental investigation of fast-action 5HF-limiter are presented; the limiter is based on the utilization of electron hetaing phenomenon in thin superconducting films. The design of SHF-limiter, which is intended for operation at liquid helium temperatures and which has the form of a section of superconducting NbN microstrip line for 1-12 GHz rang, is described.
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Nebosis, R. S., Heusinger, M. A., Schatz, W., Renk, K. F., Gol’tsman, G. N., Karasik, B. S., et al. (1993). Ultrafast photoresponse of a structured YBa2Cu3O7-δ thin film to ultrashort FIR laser pulses. IEEE Trans. Appl. Supercond., 3(1), 2160–2162.
Abstract: The authors have investigated the photoinduced voltage response of a current-carrying structured YBa2Cu3O7-δ thin film to ultrashort far-infrared (FIR) laser pulses in the frequency range from 0.7 THz to 7 THz. The detector has shown an almost constant sensitivity of 1 mV/W and a noise equivalent power of less than 5*10/sup -7/ W/ square root Hz. The temperature dependence of the decay time of the detector signal was studied for temperatures around the transition temperature of the film ( approximately 80 K). For a detector temperature where dR/dT had its maximum, the authors observed bolometric signals with decay times of about 2 ns, and for lower temperatures they observed nonbolometric signals with decay times of approximately 120 ps; the duration of the nonbolometric signals was limited by the time resolution of the electronic registration equipment.
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Банная, В. Ф., Веселова, Л. И., Гершензон, Е. М., Гусинский, Э. Н., & Литвак-Горская, Л. Б. (1990). Оценка точности метода определения раздельной концентрации примесей из измерений постоянной Холла. Физика и техника полупроводников, 24(12), 2145–2150.
Abstract: На примере p-Si⟨B,\,Ga⟩ с различной степенью компенсации проведена сравнительная оценка точности определения раздельной концентрации примесей по температурной зависимости концентрации дырок p(T) в случае одной и двух легирующих примесей с энергиями ионизации, различающимися менее чем в 2 раза. Исследована функция среднеквадратичного отклонения в пространстве параметров D(Nк, N2) (Nк, N1 и N2 — концентрации компенсирующих примесей бора и галлия соответственно, N2≫N1) в предположении, что N2, энергии B и Ga известны. Показано, что в случае двух легирующих примесей D(Nк, N1) в окрестностях минимума имеет «овражный» рельеф и при некоторых соотношениях между Nк и N1 разброс искомых величин превышает порядок, причем увеличение точности измерений p(T) существенного улучшения в вычислении параметров не дает. При одной легирующей примеси точность вычисления параметров высокая.
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