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Author Vasilev, D. D.; Malevannaya, E. I.; Moiseev, K. M.; Zolotov, P. I.; Antipov, A. V.; Vakhtomin, Y. B.; Smirnov, K. V.
Title Influence of deposited material energy on superconducting properties of the WSi films Type Conference Article
Year 2020 Publication IOP Conf. Ser.: Mater. Sci. Eng. Abbreviated Journal IOP Conf. Ser.: Mater. Sci. Eng.
Volume (down) 781 Issue Pages 012013 (1 to 6)
Keywords WSi SSPD, SNSPD
Abstract WSi thin films have the advantages for creating SNSPDs with a large active area or array of detectors on a single substrate due to the amorphous structure. The superconducting properties of ultrathin WSi films substantially depends on their structure and thickness as the NbN films. Scientific groups investigating WSi films mainly focused only on changes of their thickness and the ratio of the components on the substrate at room temperature. This paper presents experiments to determine the effect of the bias potential on the substrate, the temperature of the substrate, and the peak power of pulsed magnetron sputtering, which is the equivalent of ionization, a tungsten target, on the surface resistance and superconducting properties of the WSi ultrathin films. The negative effect of the substrate temperature and the positive effect of the bias potential and the ionization coefficient (peak current) allow one to choose the best WSi films formation mode for SNSPD: substrate temperature 297 K, bias potential -60 V, and peak current 3.5 A.
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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 1757-899X ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number Serial 1798
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Author Seleznev, V. A.; Divochiy, A. V.; Vakhtomin, Y. B.; Morozov, P. V.; Zolotov, P. I.; Vasil'ev, D. D.; Moiseev, K. M.; Malevannaya, E. I.; Smirnov, K. V.
Title Superconducting detector of IR single-photons based on thin WSi films Type Conference Article
Year 2016 Publication J. Phys.: Conf. Ser. Abbreviated Journal J. Phys.: Conf. Ser.
Volume (down) 737 Issue Pages 012032
Keywords WSi SSPD, SNSPD, NEP
Abstract We have developed the deposition technology of WSi thin films 4 to 9 nm thick with high temperature values of superconducting transition (Tc~4 K). Based on deposed films there were produced nanostructures with indicative planar sizes ~100 nm, and the research revealed that even on nanoscale the films possess of high critical temperature values of the superconducting transition (Tc~3.3-3.7 K) which certifies high quality and homogeneity of the films created. The first experiments on creating superconducting single-photon detectors showed that the detectors' SDE (system detection efficiency) with increasing bias current (I b) reaches a constant value of ~30% (for X=1.55 micron) defined by infrared radiation absorption by the superconducting structure. To enhance radiation absorption by the superconductor there were created detectors with cavity structures which demonstrated a practically constant value of quantum efficiency >65% for bias currents Ib>0.6-Ic. The minimal dark counts level (DC) made 1 s-1 limited with background noise. Hence WSi is the most promising material for creating single-photon detectors with record SDE/DC ratio and noise equivalent power (NEP).
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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 1742-6588 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number Serial 1235
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Author Divochiy, A.; Misiaszek, M.; Vakhtomin, Y.; Morozov, P.; Smirnov, K.; Zolotov, P.; Kolenderski, P.
Title Single photon detection system for visible and infrared spectrum range Type Journal Article
Year 2018 Publication Opt. Lett. Abbreviated Journal Opt. Lett.
Volume (down) 43 Issue 24 Pages 6085-6088
Keywords
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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Corporate Author Thesis
Publisher Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0146-9592 ISBN Medium
Area Expedition Conference
Notes https://arxiv.org/abs/1807.04273 Approved no
Call Number Serial 1227
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Author Moshkova, M.; Divochiy, A.; Morozov, P.; Vakhtomin, Y.; Antipov, A.; Zolotov, P.; Seleznev, V.; Ahmetov, M.; Smirnov, K.
Title High-performance superconducting photon-number-resolving detectors with 86% system efficiency at telecom range Type Journal Article
Year 2019 Publication J. Opt. Soc. Am. B Abbreviated Journal J. Opt. Soc. Am. B
Volume (down) 36 Issue 3 Pages B20
Keywords NbN PNR SSPD, SNSPD
Abstract The use of improved fabrication technology, highly disordered NbN thin films, and intertwined section topology makes it possible to create high-performance photon-number-resolving superconducting single-photon detectors (PNR SSPDs) that are comparable to conventional single-element SSPDs at the telecom range. The developed four-section PNR SSPD has simultaneously an 86±3% system detection efficiency, 35 cps dark count rate, ∼2 ns dead time, and maximum 90 ps jitter. An investigation of the PNR SSPD’s detection efficiency for multiphoton events shows good uniformity across sections. As a result, such a PNR SSPD is a good candidate for retrieving the photon statistics for light sources and quantum key distribution systems.
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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 0740-3224 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number Serial 1225
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Author Korneeva, Y. P.; Manova, N. N.; Dryazgov, M. A.; Simonov, N. O.; Zolotov, P. I.; Korneev, A. A.
Title Influence of sheet resistance and strip width on the detection efficiency saturation in micron-wide superconducting strips and large-area meanders Type Journal Article
Year 2021 Publication Supercond. Sci. Technol. Abbreviated Journal Supercond. Sci. Technol.
Volume (down) 34 Issue 8 Pages 084001
Keywords NbN SSPD, SMSPD
Abstract We report our study of detection efficiency (DE) saturation in wavelength range 400 – 1550 nm for the NbN Superconducting Microstrip Single-Photon Detectors (SMSPD) featuring the strip width up to 3 μm. We observe an expected decrease of the $DE$ saturation plateau with the increase of photon wavelength and decrease of film sheet resistance. At 1.7 K temperature DE saturation can be clearly observed at 1550 nm wavelength in strip with the width up to 2 μm when sheet resistance of the film is above 630Ω/sq. In such strips the length of the saturation plateau almost does not depend on the strip width. We used these films to make meander-shaped detectors with the light sensitive area from 20×20μm2 to a circle 50 μm in diameter. In the latter case, the detector with the strip width of 0.49 μm demonstrates saturation of DE up to 1064 nm wavelength. Although DE at 1310 and 1550 nm is not saturated, it is as high as 60%. The response time is limited by the kinetic inductance and equals to 20 ns(by 1/e decay), timing jitter is 44 ps. When coupled to multi-mode fibre large-area meanders demonstrate significantly higher dark count rate which we attribute to thermal background photons, thus advanced filtering technique would be required for practical applications.
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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 0953-2048 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number Serial 1793
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