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Author Korneev, A. A.
Title Superconducting NbN microstrip single-photon detectors Type Abstract
Year 2021 Publication Proc. Quantum Optics and Photon Counting Abbreviated Journal Proc. Quantum Optics and Photon Counting
Volume 11771 Issue Pages
Keywords (up) NbN SSPD, SNSPD
Abstract Superconducting Single-Photon Detectors (SSPD) invented two decades ago have evolved to a mature technology and have become devices of choice in the advanced applications of quantum optics, such as quantum cryptography and optical quantum computing. In these applications SSPDs are coupled to single-mode fibers and feature almost unity detection efficiency, negligible dark counts, picosecond timing jitter and MHz photon count rate. Meanwhile, there are great many applications requiring coupling to multi-mode fibers or free space. ‘Classical’ SSPDs with 100-nm-wide superconducting strip and covering area of about 100 µm2 are not suitable for further scaling due to degradation of performance and low fabrication yield. Recently we have demonstrated single-photon counting in micron-wide superconducting bridges and strips. Here we present our approach to the realization of practical photon-counting detectors of large enough area to be efficiently coupled to multi-mode fibers or free space. The detector is either a meander or a spiral of 1-µm-wide strip covering an area of 50x50 µm2. Being operated at 1.7K temperature it demonstrates the saturated detection efficiency (i.e. limited by the absorption in the detector) up to 1550 nm wavelength, about 10 ns dead time and timing jitter in range 50-100 ps.
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Corporate Author Thesis
Publisher SPIE Place of Publication Editor Prochazka, I.; Štefaňák, M.; Sobolewski, R.; Gábris, A.
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN ISBN Medium
Area Expedition Conference Quantum Optics and Photon Counting; SPIE Optics + Optoelectronics, 2021, Online Only
Notes Approved no
Call Number Serial 1784
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Author Zolotov, P.; Semenov, A.; Divochiy, A.; Goltsman, G.
Title A comparison of VN and NbN thin films towards optimal SNSPD efficiency Type Journal Article
Year 2021 Publication IEEE Trans. Appl. Supercond. Abbreviated Journal IEEE Trans. Appl. Supercond.
Volume 31 Issue 5 Pages 1-4
Keywords (up) NbN SSPD, SNSPD, WSi
Abstract Based on early phenomenological ideas about the operation of superconducting single-photon detectors (SSPD or SNSPD), it was expected that materials with a lower superconducting gap should perform better in the IR range. The plausibility of this concept could be checked using two popular SSPD materials – NbN and WSi films. However, these materials differ strongly in crystallographic structure (polycrystalline B1 versus amorphous), which makes their dependence on disorder different. In our work we present a study of the single-photon response of SSPDs made from two disordered B1 structure superconductors – vanadium nitride and niobium nitride thin films. We compare the intrinsic efficiency of devices made from films with different sheet resistance values. While both materials have a polycrystalline structure and comparable diffusion coefficient values, VN films show metallic behavior over a wide range of sheet resistance, in contrast to NbN films with an insulator-like temperature dependence of resistivity, which may be partially due to enhanced Coulomb interaction, leading to different starting points for the normal electron density of states. The results show that even though VN devices are more promising in terms of theoretical predictions, their optimal performance was not reached due to lower values of sheet resistance.
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 1051-8223 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number Serial 1223
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Author Moshkova, M. A.; Morozov, P. V.; Antipov, A. V.; Vakhtomin, Y. B.; Smirnov, K. V.
Title High-efficiency multi-element superconducting single-photon detector Type Conference Article
Year 2021 Publication Proc. SPIE Abbreviated Journal Proc. SPIE
Volume 11771 Issue Pages 2-8
Keywords (up) PNR SSPD, large active area, detection efficiency
Abstract We present the result of the creation and investigation of the multi-element superconducting single photon detectors, which can recognize the number of photons (up to six) in a short pulse of the radiation at telecommunication wavelengths range. The best receivers coupled with single-mode fiber have the system quantum efficiency of ⁓85%. The receivers have a 100 ps time resolution and a few nanoseconds dead time that allows them to operate at megahertz counting rate. Implementation of the multi-element architecture for creation of the superconducting single photon detectors with increased sensitive area allows to create the high efficiency receivers coupled with multi-mode fibers and with preserving of the all advantages of superconducting photon counters.
Address
Corporate Author Thesis
Publisher SPIE Place of Publication Editor Prochazka, I.; Štefaňák, M.; Sobolewski, R.; Gábris, A.
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN ISBN Medium
Area Expedition Conference Quantum Optics and Photon Counting
Notes Approved no
Call Number Serial 1795
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Author Smirnov, K.; Moshkova, M.; Antipov, A.; Morozov, P.; Vakhtomin, Y.
Title The cascade switching of the photon number resolving superconducting single-photon detectors Type Journal Article
Year 2021 Publication IEEE Trans. Appl. Supercond. Abbreviated Journal IEEE Trans. Appl. Supercond.
Volume 31 Issue 2 Pages 1-4
Keywords (up) PNR SSPD, SNSPD
Abstract In this article, present the first detailed study of cascade switching in superconducting photon number resolving detectors. The detectors were made in the form of four parallel nanowires, coupled with the single-mode optical fiber and mounted into a closed-cycle refrigerator with a temperature of 2.1 K. We found out the value of additional false pulses (N cas.sw. ) appearing due to cascade switching and showed that it is possible to set up the detector bias current that corresponds to a high level of the detection efficiency and a low level of N cas.sw. simultaneously. We reached the detection efficiency of 60% and N cas.sw. = 0.3%.
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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 1051-8223 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number Serial 1796
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Author Baksheeva, K.; Ozhegov, R.; Goltsman, G.; Kinev, N.; Koshelets, V.; Kochnev, A.; Betzalel, N.; Puzenko, A.; Ben Ishai, P.; Feldman, Y.
Title The sub THz emission of the human body under physiological stress Type Journal Article
Year 2021 Publication IEEE Trans. Terahertz Sci. Technol. Abbreviated Journal IEEE Trans. Terahertz Sci. Technol.
Volume Issue Pages
Keywords (up) skin sub-THz emission, medicine
Abstract We present evidence that in the sub-THz frequency band, human skin can be considered as an electromagnetic bio-metamaterial, in that its natural emission is a product of skin tissue geometry and embedded structures. Radiometry was performed on 32 human subjects from 480 to 700 GHz. Concurrently, the subjects were exposed to stress, while heart pulse rate (PS) and galvanic skin response (GSR) were also measured. The results are substantially different from the expected black body radiation signal of the skin surface. PS and GSR correlate to the emissivity. Using a simulation model for the skin, we find that the sweat duct is a critical element. The simulated frequency spectra qualitatively match the measured emission spectra and show that our sub-THz emission is modulated by our level of mental stress. This opens avenues for the remote monitoring of the human state.
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 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number 9380570 Serial 1259
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