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Author Semenov, A. D.; Hübers, H.-W.; Schubert, J.; Gol'tsman, G. N.; Elantiev, A. I.; Voronov, B. M.; Gershenzon, E. M.
Title Design and performance of the lattice-cooled hot-electron terahertz mixer Type Journal Article
Year 2000 Publication J. Appl. Phys. Abbreviated Journal J. Appl. Phys.
Volume 88 Issue 11 Pages 6758-6767
Keywords HEB mixer, charge imbalance, HF current distribution
Abstract We present the measurements and the theoreticalmodel of the frequency-dependent noise temperature of a superconductor lattice-cooled hot-electron bolometer mixer in the terahertz frequency range. The increase of the noise temperature with frequency is a cumulative effect of the nonuniform distribution of the high-frequency current in the bolometer and the charge imbalance, which occurs at the edges of the normal domain and at the contacts with normal metal. We show that under optimal operation the fluctuation sensitivity of the mixer is determined by thermodynamic fluctuations of the noise power, whereas at small biases there appears additional noise, which is probably due to the flux flow. We propose the prescription of how to minimize the influence of the current distribution on the mixer performance.
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Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN (up) 0021-8979 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number Serial 306
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Author Lusche, R.; Semenov, A.; Ilin, K.; Siegel, M.; Korneeva, Y.; Trifonov, A.; Korneev, A.; Goltsman, G.; Vodolazov, D.; Hübers, H.-W.
Title Effect of the wire width on the intrinsic detection efficiency of superconducting-nanowire single-photon detectors Type Journal Article
Year 2014 Publication J. Appl. Phys. Abbreviated Journal J. Appl. Phys.
Volume 116 Issue 4 Pages 043906 (1 to 9)
Keywords NbN SSPD, SNSPD, TaN
Abstract A thorough spectral study of the intrinsic single-photon detection efficiency in superconducting TaN and NbN nanowires with different widths has been performed. The experiment shows that the cut-off of the intrinsic detection efficiency at near-infrared wavelengths is most likely controlled by the local suppression of the barrier for vortex nucleation around the absorption site. Beyond the cut-off quasi-particle diffusion in combination with spontaneous, thermally activated vortex crossing explains the detection process. For both materials, the reciprocal cut-off wavelength scales linearly with the wire width where the scaling factor agrees with the hot-spot detection 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) 0021-8979 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number Serial 1357
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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.
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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 1526
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Author Semenov, A. D.; Il'in, K.; Siegel, M.; Smirnov, A.; Pavlov, S.; Richter, H.; Hübers, H.-W.
Title Evidence of non-bolometric mixing in the bandwidth of a hot-electron bolometer Type Journal Article
Year 2006 Publication Superconductor Science and Technology Abbreviated Journal Supercond. Sci. Technol.
Volume 19 Issue 10 Pages 1051-1056
Keywords HEB
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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 536
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Author Lusche, R.; Semenov, A.; Korneeva, Y.; Trifonov, A.; Korneev, A.; Gol'tsman, G.; Hübers, H.-W.
Title Effect of magnetic field on the photon detection in thin superconducting meander structures Type Journal Article
Year 2014 Publication Phys. Rev. B Abbreviated Journal Phys. Rev. B
Volume 89 Issue 10 Pages 104513 (1 to 7)
Keywords NbN SSPD, SNSPD
Abstract We have studied the influence of an externally applied magnetic field on the photon and dark count rates of meander-type niobium nitride superconducting nanowire single-photon detectors. Measurements have been performed at a temperature of 4.2 K, and magnetic fields up to 250 mT have been applied perpendicularly to the meander plane. While photon count rates are field independent at weak applied fields, they show a strong dependence at fields starting from approximately ±25 mT. This behavior, as well as the magnetic field dependence of the dark count rates, is in good agreement with the recent theoretical model of vortex-assisted photon detection and spontaneous vortex crossing in narrow superconducting lines. However, the local reduction of the superconducting free energy due to photon absorption, which is the fitting parameter in the model, increases much slower with the photon energy than the model predicts. Furthermore, changes in the free-energy during photon counts and dark counts depend differently on the current that flows through the meander. This indicates that photon counts and dark counts occur in different parts of the meander.
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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) 1098-0121 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number Serial 1367
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