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Author Sergeev, A. V.; Semenov, A. D.; Kouminov, P.; Trifonov, V.; Goghidze, I. G.; Karasik, B. S.; Gol’tsman, G. N.; Gershenzon, E. M.
Title Transparency of a YBa2Cu3O7-film/substrate interface for thermal phonons measured by means of voltage response to radiation Type Journal Article
Year 1994 Publication Phys. Rev. B Condens. Matter. Abbreviated Journal Phys. Rev. B Condens. Matter.
Volume 49 Issue 13 Pages 9091-9096
Keywords YBCO films
Abstract The transparency of a film/substrate interface for thermal phonons was investigated for YBa2Cu3O7 thin films deposited on MgO, Al2O3, LaAlO3, NdGaO3, and ZrO2 substrates. Both voltage response to pulsed-visible and to continuously modulated far-infrared radiation show two regimes of heat escape from the film to the substrate. That one dominated by the thermal boundary resistance at the film/substrate interface provides an initial exponential decay of the response. The other one prevailing at longer times or smaller modulation frequencies causes much slower decay and is governed by phonon diffusion in the substrate. The transparency of the boundary for phonons incident from the film on the substrate and also from the substrate on the film was determined separately from the characteristic time of the exponential decay and from the time at which one regime was changed to the other. Taking into account the specific heat of optical phonons and the temperature dependence of the group velocity of acoustic phonons, we show that the body of experimental data agrees with acoustic mismatch theory rather than with the model that assumes strong diffusive scattering of phonons at the interface.
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Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN (up) 0163-1829 ISBN Medium
Area Expedition Conference
Notes PMID:10009690 Approved no
Call Number Serial 1648
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Author Gousev, Y. P.; Gol'tsman, G. N.; Karasik, B. S.; Gershenzon, E. M.; Semenov, A. D.; Barowski, H. S.; Nebosis, R. S.; Renk, K. F.
Title Quasioptical superconducting hot electron bolometer for submillmeter waves Type Journal Article
Year 1996 Publication Int. J. of Infrared and Millimeter Waves Abbreviated Journal Int. J. of Infrared and Millimeter Waves
Volume 17 Issue 2 Pages 317-331
Keywords NbN HEB
Abstract We report on a superconducting hot electron bolometer coupled to radiation via a broadband antenna. The bolometer, a structured NbN film, was patterned on a thin dielectric membrane between terminals of a gold slotline antenna. We investigated the response to submillimeter radiation (wave-lengths ∼ 0.1 mm to 0.7 mm) in the fundamental Gaussian mode. We found that the directivity of the antenna was constant within a factor of 2.5 through the whole experimental range. The noise equivalent power of the bolometer at 119 µm was ∼ 3 · 10−13 W/Hz1/2; a time constant of ∼ 160 ps was estimated.
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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 (up) 0195-9271 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number Serial 1618
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Author Zorin, M.; Lindgren, M.; Danerud, M.; Karasik, B.; Winkler, D.; Gol'tsman, G.; Gershenzon, E.
Title Nonequilibrium and bolometric responses of YBaCuO thin films to high-frequency modulated laser radiation Type Journal Article
Year 1995 Publication J. Supercond. Abbreviated Journal J. Supercond.
Volume 8 Issue 1 Pages 11-15
Keywords YBCO HTS HEB
Abstract Picosecond nonequilibrium and slow bolometric responses to infrared radiation from a patterned high-T c superconducting (HTS) film in resistive and normal states deposited onto LaAlO3, NdGaO3, and MgO substrates were investigated using both pulse and modulation techniques. The response time of 35 ps to a laser pulse of 17 ps FWHM has been observed. The intrinsic response time of the fast process is expected to be about a few picoseconds. The modulation technique, being free from the disadvantages of pulse methods (poor sensitivity, limited dynamic range), makes the detailed study of a number of relaxation processes possible. Besides the nonequilibrium response, two kinds of bolometric processes, namely phonon transport through the film-substrate interface and phonon thermal diffusion in a substrate, manifest themselves in certain frequency dependences.
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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 (up) 0896-1107 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number Serial 1630
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Author Gol'tsman, G. N.; Goghidze, I. G.; Kouminov, P. B.; Karasik, B. S.; Semenov, A. D.; Gershenzon, E. M.
Title Influence of grain boundary weak links on the nonequilibrium response of YBaCuO thin films to short laser pulses Type Journal Article
Year 1994 Publication J. Supercond. Abbreviated Journal J. Supercond.
Volume 7 Issue 4 Pages 751-755
Keywords YBCO HTS detector, nonequilibrium response
Abstract The transient voltage response in both epitaxial and granular YBaCuO thin films to 80 ps pulses of YAG∶Nd laser radiation of wavelength 0.63 and 1.54 μm was studied. In the normal and resistive states both types of films demonstrate two components: a nonequilibrium picosecond component and a bolometric nanosecond one. The normalized amplitudes are almost the same for all films. In the superconducting state we observed a kinetic inductive response and two-component shape after integration. The normalized amplitude of the response in granular films is up to five orders of magnitude larger than in epitaxial films. We interpret the nonequilibrium response in terms of a suppression of the order parameter by the excess of quasiparticles followed by the change of resistance in the normal and resistive states or kinetic inductance in the superconducting state. The sharp rise of inductive response in granular films is explained both by a diminishing of the cross section for current percolation through the disordered network of Josephson weak links and by a decrease of condensate density in neighboring regions.
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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 (up) 0896-1107 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number Serial 1636
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Author Sergeev, A.; Semenov, A.; Trifonov, V.; Karasik, B.; Gol'tsman, G.; Gershenzon, E.
Title Heat transfer in YBaCuO thin film/sapphire substrate system Type Journal Article
Year 1994 Publication J. Supercond. Abbreviated Journal J. Supercond.
Volume 7 Issue 2 Pages 341-344
Keywords YBCO films
Abstract The thermal boundary resistance at the YBaCuO thin film/Al2O3 substrate interface was investigated. The transparency for thermal phonons incident on the interface as well as for phonons moving from the substrate was determined. We have measured a transient voltage response of current-biased films to continuously modulated radiation. The observed knee in the modulation frequency dependence of the response reflects the crossover from the diffusion regime to the contact resistance regime of the heat transfer across the interface. The values of transparency were independently deduced both from the phonon escape time and from the time of phonon return to the film which were identified with peculiarities in the frequency dependence. The results are much more consistent with the acoustic mismatch theory than the diffuse mismatch model.
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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 (up) 0896-1107 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number Serial 1647
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Author Sergeev, A.; Karasik, B. S.; Ptitsina, N. G.; Chulkova, G. M.; Il'in, K. S.; Gershenzon, E. M.
Title Electron–phonon interaction in disordered conductors Type Journal Article
Year 1999 Publication Phys. Rev. B Condens. Matter Abbreviated Journal Phys. Rev. B Condens. Matter
Volume 263-264 Issue Pages 190-192
Keywords disordered conductors, electron-phonon interaction
Abstract The electron–phonon interaction is strongly modified in conductors with a small value of the electron mean free path (impure metals, thin films). As a result, the temperature dependencies of both the inelastic electron scattering rate and resistivity differ significantly from those for pure bulk materials. Recent complex measurements have shown that modified dependencies are well described at K by the electron interaction with transverse phonons. At helium temperatures, available data are conflicting, and cannot be described by an universal model.
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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 (up) 0921-4526 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number Serial 1765
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Author Karasik, B.S.; Milostnaya, I.I.; Zorin, M.A.; Elantev, A.I.; Gol'tsman, G.N.; Gershenzon, E.M.
Title Subnanosecond S-N and N-S switching of YBCO film induced by current pulse Type Journal Article
Year 1994 Publication Phys. C: Supercond. Abbreviated Journal Phys. C: Supercond.
Volume 235-240 Issue Pages 1981-1982
Keywords YBCO HTS switches
Abstract A transition of YBCO bridge 60 nm thick from superconducting to normal state induced by an abrupt current step has been studied. A subnanosecond stage has been observed during both S-N and N-S transition. The data obtained can be explained by hot-electron phenomena. On the basis of experimental results a prediction of picosecond switch performance has been made.
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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 (up) 0921-4534 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number Serial 1633
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Author Danerud, M.; Winkler, D.; Lindgren, M.; Zorin, M.; Trifonov, V.; Karasik, B.; Gershenzon, E. M.; Gol'tsman, G. N.
Title A fast infrared detector based on patterned YBCO thin film Type Journal Article
Year 1994 Publication Supercond. Sci. Technol. Abbreviated Journal Supercond. Sci. Technol.
Volume 7 Issue 5 Pages 321-323
Keywords YBCO HTS detector
Abstract Detectors for infrared radiation ( lambda =0.85 mu m) were made of 50 nm thick YBa2Cu3O7- delta films on LaAlO3 and MgO or 60 nm thick films on NdGaO3. Parallel strips (1 mu m wide by 20 mu m long) were patterned in the films and formed the active device. These devices were designed to detect short infrared laser pulses by electron heating. The detectors were current biased into the resistive and the normal states. The response was studied in direct pulse measurements as well as by amplitude modulation of a laser. The pulse measurements showed a fast picosecond response followed by a slower decay related to phonon escape through the film-substrate interface and heat diffusion in the substrate. The frequency spectra up to 10 GHz showed two slopes with a knee corresponding to the phonon escape time.
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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 (up) 0953-2048 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number Serial 1646
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Author Gol'tsman, G. N.; Karasik, B. S.; Okunev, O. V.; Dzardanov, A. L.; Gershenzon, E. M.; Ekstrom, H.; Jacobsson, S.; Kollberg, E.
Title NbN hot electron superconducting mixers for 100 GHz operation Type Journal Article
Year 1995 Publication IEEE Trans. Appl. Supercond. Abbreviated Journal IEEE Trans. Appl. Supercond.
Volume 5 Issue 2 Pages 3065-3068
Keywords NbN HEB mixers
Abstract NbN is a promising superconducting material for hot-electron superconducting mixers with an IF bandwidth larger than 1 GHz. In the 1OO GHz frequency range, the following parameters were obtained for 50 /spl Aring/ thick NbN films at 4.2 K: receiver noise temperature (DSB) /spl sim/1000 K; conversion loss /spl sim/10 dB; IF bandwidth /spl sim/1 GHz; and local oscillator power /spl sim/1 /spl mu/W. An increase of the critical current of the NbN film, increased working temperature, and a better mixer matching may allow a broader IF bandwidth up to 2 GHz, reduced conversion losses down to 3-5 dB and a receiver noise temperature (DSB) down to 200-300 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
Series Volume Series Issue Edition
ISSN (up) 1051-8223 ISBN Medium
Area Expedition Conference
Notes About LO power required Approved no
Call Number Serial 255
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Author Zorin, M.; Gol'tsman, G.N.; Karasik, B.S.; Elantev, A.I.; Gershenzon, E.M.; Lindgren, M.; Danerud, M.; Winkler, D.
Title Optical mixing in thin YBa2Cu3O7-x films Type Journal Article
Year 1995 Publication IEEE Trans. Appl. Supercond. Abbreviated Journal IEEE Trans. Appl. Supercond.
Volume 5 Issue 2 Pages 2431-2434
Keywords YBCO HTS HEB mixers
Abstract High quality, j/sub c/ (77 K)>10/sup 6/ A/cm/sup 2/, epitaxial YBa2Cu3O7-x films of 50 nm thickness were patterned into ten parallel 1 /spl mu/m wide strips. The film structure was coupled to a single-mode fiber. Mixer response was obtained at 0.78 /spl mu/m using laser frequency modulation and an optical delay line. Using two semiconductor lasers at 1.55 /spl mu/m wavelength the beating signal was used to measure the photoresponse up to 18 GHz. Nonequilibrium photoresponse in the resistive state of the superconductor was observed. Bolometric response dominates up to 3 GHz, after which the nonequilibrium response is constant up to the frequency limit of our registration system. Using an electron heating model the influence of different thermal processes on the conversion loss has been analyzed. Ways of increasing the sensitivity are also discussed.
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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 (up) 1051-8223 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number Serial 1619
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