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Author Sidorova, M. V.; Kozorezov, A. G.; Semenov, A. V.; Korneeva, Y. P.; Mikhailov, M. Y.; Devizenko, A. Y.; Korneev, A. A.; Chulkova, G. M.; Goltsman, G. N.
Title Nonbolometric bottleneck in electron-phonon relaxation in ultrathin WSi films Type Journal Article
Year (down) 2018 Publication Phys. Rev. B Abbreviated Journal Phys. Rev. B
Volume 97 Issue 18 Pages 184512 (1 to 13)
Keywords WSi films, diffusion constant, SSPD, SNSPD
Abstract We developed the model of the internal phonon bottleneck to describe the energy exchange between the acoustically soft ultrathin metal film and acoustically rigid substrate. Discriminating phonons in the film into two groups, escaping and nonescaping, we show that electrons and nonescaping phonons may form a unified subsystem, which is cooled down only due to interactions with escaping phonons, either due to direct phonon conversion or indirect sequential interaction with an electronic system. Using an amplitude-modulated absorption of the sub-THz radiation technique, we studied electron-phonon relaxation in ultrathin disordered films of tungsten silicide. We found an experimental proof of the internal phonon bottleneck. The experiment and simulation based on the proposed model agree well, resulting in τe−ph∼140–190 ps at TC=3.4K, supporting the results of earlier measurements by independent techniques.
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Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2469-9950 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number Serial 1305
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Author Sidorova, M.; Semenov, A.; Korneev, A.; Chulkova, G.; Korneeva, Y.; Mikhailov, M.; Devizenko, A.; Kozorezov, A.; Goltsman, G.
Title Electron-phonon relaxation time in ultrathin tungsten silicon film Type Miscellaneous
Year (down) 2018 Publication arXiv Abbreviated Journal
Volume Issue Pages
Keywords WSi film
Abstract Using amplitude-modulated absorption of sub-THz radiation (AMAR) method, we studied electron-phonon relaxation in thin disordered films of tungsten silicide. We found a response time ~ 800 ps at critical temperature Tc = 3.4 K, which scales as minus 3 in the temperature range from 1.8 to 3.4 K. We discuss mechanisms, which can result in a strong phonon bottle-neck effect in a few nanometers thick film and yield a substantial difference between the measured time, characterizing response at modulation frequency, and the inelastic electron-phonon relaxation time. We estimate the electron-phonon relaxation time to be in the range ~ 100-200 ps at 3.4 K.
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Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
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ISSN ISBN Medium
Area Expedition Conference
Notes Duplicated as 1341 Approved no
Call Number Serial 1340
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Author Sidorova, M. V.; Kozorezov, A. G.; Semenov, A. V.; Korneev, A. A.; Chulkova, G. M.; Korneeva, Y. P.; Mikhailov, M. Y.; Devizenko, A. Y.; Goltsman, G. N.
Title Non-bolometric bottleneck in electron-phonon relaxation in ultra-thin WSi film Type Miscellaneous
Year (down) 2018 Publication arXiv Abbreviated Journal
Volume Issue Pages
Keywords WSi films, diffusion constant, SSPD, SNSPD
Abstract We developed the model of the internal phonon bottleneck to describe the energy exchange between the acoustically soft ultrathin metal film and acoustically rigid substrate. Discriminating phonons in the film into two groups, escaping and nonescaping, we show that electrons and nonescaping phonons may form a unified subsystem, which is cooled down only due to interactions with escaping phonons, either due to direct phonon conversion or indirect sequential interaction with an electronic system. Using an amplitude-modulated absorption of the sub-THz radiation technique, we studied electron-phonon relaxation in ultrathin disordered films of tungsten silicide. We found an experimental proof of the internal phonon bottleneck. The experiment and simulation based on the proposed model agree well, resulting in tau{e-ph} = 140-190 ps at TC = 3.4 K, supporting the results of earlier measurements by independent techniques.
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 Duplicated as 1305 Approved no
Call Number Serial 1341
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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 (down) 2017 Publication Proc. SPIE Abbreviated Journal Proc. SPIE
Volume 10313 Issue Pages 103130F (1 to 3)
Keywords NbN SSPD, SNSPD
Abstract 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
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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 Korneeva, Y.; Sidorova, M.; Semenov, A.; Krasnosvobodtsev, S.; Mitsen, K.; Korneev, A.; Chulkova, G.; Goltsman, G.
Title Comparison of hot-spot formation in NbC and NbN single-photon detectors Type Journal Article
Year (down) 2016 Publication IEEE Trans. Appl. Supercond. Abbreviated Journal IEEE Trans. Appl. Supercond.
Volume 26 Issue 3 Pages 1-4
Keywords NbC, NbN SSPD, SNSPD
Abstract We report an experimental investigation of the hot-spot evolution in superconducting single-photon detectors made of disordered superconducting materials with different diffusivity and energy downconversion time values, i.e., 33-nm-thick NbN and 23-nm-thick NbC films. We have demonstrated that, in NbC film, only 405-nm photons produce sufficiently large hot spot to trigger a single-photon response. The dependence of detection efficiency on bias current for 405-nm photons in NbC is similar to that for 3400-nm photons in NbN. In NbC, large diffusivity and downconversion time result in 1-D critical current suppression profile compared with the usual 2-D profile in NbN.
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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 1348
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