|   | 
Details
   web
Records
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.
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 (up) 0896-1107 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number Serial 1636
Permanent link to this record
 

 
Author Gousev, Y. P.; Semenov, A. D.; Gol'tsman, G. N.; Sergeev, A. V.; Gershenzon, E. M.
Title Electron-phonon interaction in disordered NbN films Type Journal Article
Year 1994 Publication Phys. B Condens. Mat. Abbreviated Journal Phys. B Condens. Mat.
Volume 194-196 Issue Pages 1355-1356
Keywords NbN films
Abstract Electron-phonon interaction time has been investigated in disordered films of NbN. A temperatures below 5.5 K tau_eph ~ T -1"6 which is attributed to the renormalisation of phonon spectrum in thin films.
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 (up) 0921-4526 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number Serial 1649
Permanent link to this record
 

 
Author Semenov, A. D.; Hübers, H.-W.; Richter, H.; Birk, M.; Krocka, M.; Mair, U.; Smirnov, K.; Gol'tsman, G. N.; Voronov, B. M.
Title 2.5 THz heterodyne receiver with NbN hot-electron-bolometer mixer Type Journal Article
Year 2002 Publication Phys. C: Supercond. Abbreviated Journal Phys. C: Supercond.
Volume 372-376 Issue Pages 448-453
Keywords NbN HEB mixers, applications
Abstract We describe a 2.5 THz heterodyne receiver for applications in astronomy and atmospheric research. The receiver employs a superconducting NbN phonon-cooled hot-electron-bolometer mixer and an optically pumped far-infrared gas laser as local oscillator. 2200 K double sideband mixer noise temperature was measured at 2.5 THz across a 1 GHz intermediate frequency bandwidth centred at 1.5 GHz. The total conversion losses were 17 dB. The mixer response was linear at load temperatures smaller than 400 K. The receiver was tested in the laboratory environment by measuring the methanol line in emission. Observed pressure broadening confirms the true heterodyne detection regime of the mixer.
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 (up) 0921-4534 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number Serial 1526
Permanent link to this record
 

 
Author Gershenzon, E. M.; Gol'tsman, G. N.; Gogidze, I. G.; Semenov, A. D.; Sergeev, A. V.
Title Processes of electron-phonon interaction in thin YBaCuO films Type Journal Article
Year 1991 Publication Phys. C: Supercond. Abbreviated Journal Phys. C: Supercond.
Volume 185-189 Issue Pages 1371-1372
Keywords YBCO HTS detectors
Abstract The ultrafast voltage response of YBaCuO films to laser radiation is studied and compared with previously investigated quasiparicles response to radiation of submillimeter wavelength range. Voltage shift under the visible light radiation has two components. Picosecond response realized as suppression superconductivity by nonequilibrium excess quasiparticles, response time is determined by quasiparticles recombination rate. Nanosecond response is probably due to bolometric effect.
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 (up) 0921-4534 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number Serial 1676
Permanent link to this record
 

 
Author Gol'tsman, G. N.; Semenov, A. D.; Gousev, Y. P.; Zorin, M. A.; Gogidze, I. G.; Gershenzon, E. M.; Lang, P. T.; Knott, W. J.; Renk, K. F.
Title Sensitive picosecond NbN detector for radiation from millimetre wavelengths to visible light Type Journal Article
Year 1991 Publication Supercond. Sci. Technol. Abbreviated Journal Supercond. Sci. Technol.
Volume 4 Issue 9 Pages 453-456
Keywords NbN HEB detectors
Abstract The authors report on the application of a broad-band NbN film detector which has high sensitivity and picosecond response time for detection of radiation from millimetre wavelengths to visible light. From a study of amplitude modulated radiation of backward-wave tubes and picosecond pulses from gas and solid state lasers at wavelengths between 2 mm and 0.53 mu m, they found a detectivity of 1010 W-1 cm Hz-1/2 and a response time of less than 50 ps at T=10 K. The characteristics were provided by using a 150 AA thick NbN film patterned into a structure of micron strips. According to the proposed detection mechanism, namely electron heating, they expect an intrinsic response time of approximately 20 ps at the same temperature.
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 (up) 0953-2048 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number Serial 242
Permanent link to this record