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Author Ozhegov, R. V.; Smirnov, A. V.; Vakhtomin, Yu. B.; Smirnov, K. V.; Divochiy, A. V.; Goltsman, G. N.
Title Ultrafast superconducting bolometer receivers for terahertz applications Type Abstract
Year 2009 Publication Proc. PIERS Abbreviated Journal Proc. PIERS
Volume Issue Pages 867
Keywords HEB
Abstract (up) The research by the group of Moscow State Pedagogical University into the hot-electron phenomena in thin superconducting films has led to the development of new types of detectors and their use both in fundamental and applied studies. In this paper, we present the results of testing the terahertz HEB receiver systems based on ultrathin (∼ 4 nm) NbN and MoRe detectors with a response time of 50 ps and 1 ns, respectively. We have developed three types of devices which differ in the way a terahertz signal is coupled to the detector and cover the following ranges: 0.3–3 THz, 0.1–30 THz and 25–70 THz. In the case of the receiving system optimized for 0.3–3 THz, the sensitive element (a strip of asuperconductor with planar dimensions of 0.2μm (length) by 1.7μm (width)) was integrated witha planar broadband log-spiral antenna. For additional focusing ofthe incident radiation a silicon hyperhemispherical lens was used. For the 0.1–30 THz receivingsystem, the sensitive element was patterned as parallel strips(2μm wide each) filling an area of 500×500μm2with a filling factor of 0.5. In the receivingsystem of this type we used direct coupling of the incident radiation to the sensitive element. Inthe 25–70 THz range (detector type 2/2a in Table 1) we used a square-shaped superconductingdetector with planar dimensions of 10×10μm2. Incident radiation was coupled to the detectorwith the use of a germanium hyperhemispherical lens.The response time of the above receiving systems is determined by the cooling rate of the hotelectrons in the film. That depends on the electron-phonon interaction time, which is less forultrathin NbN than in MoRe.
Address Moscow, Russia
Corporate Author Thesis
Publisher The Electromagnetics Academy Place of Publication 777 Concord Avenue, Suite 207 Cambridge, MA 02138 Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1559-9450 ISBN 978-1-934142-09-7 Medium
Area Expedition Conference
Notes Approved no
Call Number RPLAB @ sasha @ ozhegovultrafast Serial 1022
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Author Smirnov, K. V.; Vakhtomin, Yu. B.; Divochiy, A. V.; Ozhegov, R. V.; Pentin, I. V.; Slivinskaya, E. V.; Tarkhov, M. A.; Gol’tsman, G. N.
Title Single-photon detectors for the visible and infrared parts of the spectrum based on NbN nanostructures Type Abstract
Year 2009 Publication Proc. Progress In Electromagnetics Research Symp. Abbreviated Journal Proc. Progress In Electromagnetics Research Symp.
Volume Issue Pages 863-864
Keywords SSPD, SNSPD
Abstract (up) The research by the group of Moscow State Pedagogical University into the hot-electron phenomena in thin superconducting films has led to the development of new types ofdetectors [1, 2] and their use both in fundamental and applied studies [3–6]. In this paper, wepresent the results of the development and fabrication of receiving systems for the visible andinfrared parts of the spectrum optimised for use in telecommunication systems and quantumcryptography.
Address
Corporate Author Thesis
Publisher Place of Publication Moscow, Russia Editor
Language Summary Language Original Title
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Notes Approved no
Call Number RPLAB @ sasha @ smirnovsession Serial 1050
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Author Goltsman, G.; Korneev, A.; Divochiy, A.; Minaeva, O.; Tarkhov, M.; Kaurova, N.; Seleznev, V.; Voronov, B.; Okunev, O.; Antipov, A.; Smirnov, K.; Vachtomin, Yu.; Milostnaya, I.; Chulkova, G.
Title Ultrafast superconducting single-photon detector Type Journal Article
Year 2009 Publication J. Modern Opt. Abbreviated Journal J. Modern Opt.
Volume 56 Issue 15 Pages 1670-1680
Keywords SSPD, SNSPD
Abstract (up) The state-of-the-art of the NbN nanowire superconducting single-photon detector technology (SSPD) is presented. The SSPDs exhibit excellent performance at 2 K temperature: 30% quantum efficiency from visible to infrared, negligible dark count rate, single-photon sensitivity up to 5.6 µm. The recent achievements in the development of GHz counting rate devices with photon-number resolving capability is presented.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0950-0340 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number RPLAB @ akorneev @ Serial 607
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Author Ovchinnikov, Yu. N.; Varlamov, A. A.
Title Fluctuation-dissipative phenomena in a narrow superconducting channel carrying current below critical Type Journal Article
Year 2009 Publication arXiv Abbreviated Journal
Volume 0910.2659v1 Issue Pages 1-4
Keywords superconducting nanowire, resistance calculation
Abstract (up) The theory of current transport in a narrow superconducting channel accounting for thermal fluctuations is developed. These fluctuations result in the appearance of small but finite dissipation in the sample. The value of corresponding voltage is found as the function of temperature (close to transition temperature) and arbitrary bias current. It is demonstrated that the value of the activation energy (exponential factor in the Arrenius law) when current approaches to the critical one is proportional to (1-J/Jc)^(5/4). This result is in concordance with the one for the affine phenomenon of the Josephson current decay due to the thermal phase fluctuations, where the activation energy proportional (1-J/J_c)^(3/2)(the difference in the exponents is related to the additional current dependence of the order parameter). Found dependence of the activation energy on current explains the enormous discrepancy between the theoretically predicted before and the experimentally observed broadening of the resistive transition.
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Notes arXiv:0910.2659v1; 4 pages, 3 figures Approved no
Call Number Serial 931
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Author Karpowicz, Nicholas; Lu, Xiaofei; Zhang, X.-C.
Title Terahertz gas photonics Type Journal Article
Year 2009 Publication J. Modern Opt. Abbreviated Journal
Volume 56 Issue 10 Pages 1137-1150
Keywords
Abstract (up) The underlying physics of the generation and detection of terahertz (THz) waves in gases are described. The THz wave generation process takes place in two steps: asymmetric gas ionization by two-frequency laser fields, followed by interaction of the ionized electron wave packets with the surrounding medium, producing an intense ‘echo' with tunable spectral content. In order to clarify the physical picture at the moment of ionization, the laser–atom interaction is treated through solution of the time-dependent Schrödinger equation, yielding an ab initio understanding of the release of the electron wave packets. The second step, where the electrons interact with the surrounding plasma is treated analytically. The resulting pressure dependence of the THz radiation is explored in detail. The THz wave detection process is shown to be the result of four-wave mixing, leading to analytical expressions of the signal obtained which allow for improved optimization of systems that exploit these effects.
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Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number RPLAB @ gujma @ Serial 670
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