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Author Samsonova, A. S.; Zolotov, P. I.; Baeva, E. M.; Lomakin, A. I.; Titova, N. A.; Kardakova, A. I.; Goltsman, G. N.
Title Signatures of surface magnetic disorder in niobium films Type Journal Article
Year 2021 Publication IEEE Trans. Appl. Supercond. Abbreviated Journal IEEE Trans. Appl. Supercond.
Volume (down) 31 Issue 5 Pages 1-5
Keywords Nb films
Abstract We present our studies on the evolution of the normal and superconducting properties with thickness of thin Nb films with a low level of non-magnetic disorder ( kFl≈150 for the thickest film in the set). The analysis of the superconducting behavior points to the presence of magnetic moments, hidden in the native oxide on the surface of Nb films. Using the Abrikosov-Gorkov theory, we obtain the density of surface magnetic moments of 1013 cm −2 , which is in agreement with the previously reported data for Nb films.
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ISSN 1051-8223 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number Serial 1792
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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 (down) 31 Issue 2 Pages 1-4
Keywords 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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Language Summary Language Original Title
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ISSN 1051-8223 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number Serial 1796
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Author Polyakova, M.; Semenov, A. V.; Kovalyuk, V.; Ferrari, S.; Pernice, W. H. P.; Gol'tsman, G. N.
Title Protocol of measuring hot-spot correlation length for SNSPDs with near-unity detection efficiency Type Journal Article
Year 2019 Publication IEEE Trans. Appl. Supercond. Abbreviated Journal IEEE Trans. Appl. Supercond.
Volume (down) 29 Issue 5 Pages 1-5
Keywords SSPD, waveguide-integrated SNSPD, hot-spot interaction length
Abstract We present a simple quantum detector tomography protocol, which allows, without ambiguities, to measure the two-spot detection efficiency and extract the hot-spot interaction length of superconducting nanowire single photon detectors (SNSPDs) with unity intrinsic detection efficiency. We identify a significant parasitic contribution to the measured two-spot efficiency, related to an effect of the bias circuit, and find a way to rule out this contribution during data post-processing and directly in the experiment. From the data analysis for waveguide-integrated SNSPD, we find signatures of the saturation of the two-spot efficiency and hot-spot interaction length of order of 100 nm.
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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 1187
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Author Korneev, A.; Korneeva, Y.; Florya, I.; Semenov, A.; Goltsman, G.
Title Photon switching statistics in multistrip superconducting single-photon detectors Type Journal Article
Year 2018 Publication IEEE Trans. Appl. Supercond. Abbreviated Journal IEEE Trans. Appl. Supercond.
Volume (down) 28 Issue 7 Pages 1-4
Keywords SSPD, SNSPD
Abstract We study photon count statistics in superconducting single-photon detectors consisting of up to 70 narrow superconducting strips connected in parallel. Using interarrival time analysis, we demonstrate that our samples are operated in the “arm-trigger” regime and require up to seven subsequently absorbed photons to form a resistive state in the whole sample. We also performed numerical simulation of the light and dark count rates versus detector bias current, which are in good agreement with the experimental results.
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Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
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ISSN 1051-8223 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number Serial 1304
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Author Lobanov, Y.; Shcherbatenko, M.; Semenov, A.; Kovalyuk, V.; Kahl, O.; Ferrari, S.; Korneev, A.; Ozhegov, R.; Kaurova, N.; Voronov, B. M.; Pernice, W. H. P.; Gol'tsman, G. N.
Title Superconducting nanowire single photon detector for coherent detection of weak signals Type Journal Article
Year 2017 Publication IEEE Trans. Appl. Supercond. Abbreviated Journal IEEE Trans. Appl. Supercond.
Volume (down) 27 Issue 4 Pages 1-5
Keywords NbN SSPD mixer, SNSPD, nanophotonic waveguide
Abstract Traditional photon detectors are operated in the direct detection mode, counting incident photons with a known quantum efficiency. Here, we have investigated a superconducting nanowire single photon detector (SNSPD) operated as a photon counting mixer at telecommunication wavelength around 1.5 μm. This regime of operation combines excellent sensitivity of a photon counting detector with excellent spectral resolution given by the heterodyne technique. Advantageously, we have found that low local oscillator (LO) power of the order of hundreds of femtowatts to a few picowatts is sufficient for clear observation of the incident test signal with the sensitivity approaching the quantum limit. With further optimization, the required LO power could be significantly reduced, which is promising for many practical applications, such as the development of receiver matrices or recording ultralow signals at a level of less-than-one-photon per second. In addition to a traditional NbN-based SNSPD operated with normal incidence coupling, we also use detectors with a travelling wave geometry, where a NbN nanowire is placed on the top of a Si 3 N 4 nanophotonic waveguide. This approach is fully scalable and a large number of devices could be integrated on a single chip.
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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 1206
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