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Author Krause, S.; Mityashkin, V.; Antipov, S.; Gol’tsman, G.; Meledin, D.; Desmaris, V.; Belitsky, V.; Rudziński, M.
Title Reduction of phonon escape time for nbn hot electron bolometers by using gan buffer layers Type Journal Article
Year 2017 Publication IEEE Trans. Terahertz Sci. Technol. Abbreviated Journal IEEE Trans. Terahertz Sci. Technol.
Volume 7 Issue 1 Pages 53-59
Keywords NbN HEB mixer
Abstract (up) In this paper, we investigated the influence of the GaN buffer layer on the phonon escape time of phonon-cooled hot electron bolometers (HEBs) based on NbN material and compared our findings to conventionally employed Si substrate. The presented experimental setup and operation of the HEB close to the critical temperature of the NbN film allowed for the extraction of phonon escape time in a simplified manner. Two independent experiments were performed at GARD/Chalmers and MSPU on a similar experimental setup at frequencies of approximately 180 and 140 GHz, respectively, and have shown reproducible and consistent results. By fitting the normalized IF measurement data to the heat balance equations, the escape time as a fitting parameter has been deduced and amounts to 45 ps for the HEB based on Si substrate as in contrast to a significantly reduced escape time of 18 ps for the HEB utilizing the GaN buffer layer under the assumption that no additional electron diffusion has taken place. This study indicates a high phonon transmissivity of the NbN-to-GaN interface and a prospective increase of IF bandwidth for HEB made of NbN on GaN buffer layers, which is desirable for future THz HEB heterodyne receivers.
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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 2156-3446 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number Serial 1330
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Author Antipov, S.; Trifonov, A.; Krause, S.; Meledin, D.; Desmaris, V.; Belitsky, V.; Gol’tsman, G.
Title Gain bandwidth of NbN HEB mixers on GaN buffer layer operating at 2 THz local oscillator frequency Type Conference Article
Year 2017 Publication Proc. 28th Int. Symp. Space Terahertz Technol. Abbreviated Journal Proc. 28th Int. Symp. Space Terahertz Technol.
Volume Issue Pages 147-148
Keywords NbN HEB mixers, GaN buffer-layer, IF bandwidth
Abstract (up) In this paper, we present IF bandwidth measurement results of NbN HEB mixers, which are employing NbN thin films grown on a GaN buffer-layer. The HEB mixers were operated in the heterodyne regime at a bath temperature of approximately 4.5 K and with a local oscillator operating at a frequency of 2 THz. A quantum cascade laser served as the local oscillator and a reference synthesizer based on a BWO generator (130-160 GHz) and a semiconductor superlattice (SSL) frequency multiplier was used as a signal source. By changing the LO frequency it was possible to record the IF response or gain bandwidth of the HEB with a spectrum analyzer at the operation point, which yielded lowest noise temperature. The gain bandwidth that was recorded in the heterodyne regime at 2 THz amounts to approximately 5 GHz and coincides well with a measurement that has been performed at elevated bath temperatures and lower LO frequency of 140 GHz. These findings strongly support that by using a GaN buffer-layer the phonon escape time of NbN HEBs can be significantly lower as compared to e.g. Si substrate, thus, providing higher gain bandwidth.
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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 Serial 1175
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Author Zhang, J.; Verevkin, A.; Slysz, W.; Chulkova, G.; Korneev, A.; Lipatov, A.; Okunev, O.; Gol’tsman, G. N.; Sobolewski, Roman
Title Time-resolved characterization of NbN superconducting single-photon optical detectors Type Conference Article
Year 2017 Publication Proc. SPIE Abbreviated Journal Proc. SPIE
Volume 10313 Issue Pages 103130F (1 to 3)
Keywords NbN SSPD, SNSPD
Abstract (up) NbN superconducting single-photon detectors (SSPDs) are very promising devices for their picosecond response time, high intrinsic quantum efficiency, and high signal-to-noise ratio within the radiation wavelength from ultraviolet to near infrared (0.4 gm to 3 gm) [1-3]. The single photon counting property of NbN SSPDs have been investigated thoroughly and a model of hotspot formation has been introduced to explain the physics of the photon- counting mechanism [4-6]. At high incident flux density (many-photon pulses), there are, of course, a large number of hotspots simultaneously formed in the superconducting stripe. If these hotspots overlap with each other across the width w of the stripe, a resistive barrier is formed instantly and a voltage signal can be generated. We assume here that the stripe thickness d is less than the electron diffusion length, so the hotspot region can be considered uniform. On the other hand, when the photon flux is so low that on average only one hotspot is formed across w at a given time, the formation of the resistive barrier will be realized only when the supercurrent at sidewalks surpasses the critical current (jr) of the superconducting stripe [1]. In the latter situation, the formation of the resistive barrier is associated with the phase-slip center (PSC) development. The effect of PSCs on the suppression of superconductivity in nanowires has been discussed very recently [8, 9] and is the subject of great interest.
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Corporate Author Thesis
Publisher SPIE Place of Publication Editor Armitage, J. C.
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN ISBN Medium
Area Expedition Conference Opto-Canada: SPIE Regional Meeting on Optoelectronics, Photonics, and Imaging, 2002, Ottawa, Ontario, Canada
Notes Downloaded from http://www2.ece.rochester.edu/projects/ufqp/PDF/2002/213NbNTimeOPTO_b.pdf This artcle was published in 2017 with only first author indicated (Zhang, J.). There were 8 more authors! Approved no
Call Number Serial 1750
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Author Elezov, M. S.; Ozhegov, R. V.; Goltsman, G. N.; Makarov, V.
Title Development of the experimental setup for investigation of latching of superconducting single-photon detector caused by blinding attack on the quantum key distribution system Type Conference Article
Year 2017 Publication EPJ Web of Conferences Abbreviated Journal EPJ Web of Conferences
Volume 132 Issue 2 Pages 2
Keywords
Abstract (up) Recently bright-light control of the SSPD has been

demonstrated. This attack employed a “backdoor” in the detector biasing

scheme. Under bright-light illumination, SSPD becomes resistive and

remains “latched” in the resistive state even when the light is switched off.

While the SSPD is latched, Eve can simulate SSPD single-photon response

by sending strong light pulses, thus deceiving Bob. We developed the

experimental setup for investigation of a dependence on latching threshold

of SSPD on optical pulse length and peak power. By knowing latching

threshold it is possible to understand essential requirements for

development countermeasures against blinding attack on quantum key

distribution system with SSPDs.
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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 @ kovalyuk @ Serial 1116
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Author Elezov, M. S.; Ozhegov, R. V.; Goltsman, G. N.; Makarov, V.; Vinogradov, E. A.; Naumov, A. V.; Gladush, M. G.; Karimullin, K. R.
Title Development of the experimental setup for investigation of latching of superconducting single-photon detector caused by blinding attack on the quantum key distribution system Type Conference Article
Year 2017 Publication EPJ Web Conf. Abbreviated Journal EPJ Web Conf.
Volume 132 Issue Pages 01004 (1 to 2)
Keywords QKD, SSPD, SNSPD
Abstract (up) Recently bright-light control of the SSPD has been demonstrated. This attack employed a “backdoor” in the detector biasing scheme. Under bright-light illumination, SSPD becomes resistive and remains “latched” in the resistive state even when the light is switched off. While the SSPD is latched, Eve can simulate SSPD single-photon response by sending strong light pulses, thus deceiving Bob. We developed the experimental setup for investigation of a dependence on latching threshold of SSPD on optical pulse length and peak power. By knowing latching threshold it is possible to understand essential requirements for development countermeasures against blinding attack on quantum key distribution system with SSPDs.
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 2100-014X ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number Serial 1327
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