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Author Gol'tsman, G.; Maslennikov, S.; Finkel, M.; Antipov, S.; Kaurova, N.; Grishina, E.; Polyakov, S.; Vachtomin, Y.; Svechnikov, S.; Smirnov, K.; Voronov, B.
Title Nanostructured ultrathin NbN film as a terahertz hot-electron bolometer mixer Type Conference Article
Year 2006 Publication Proc. MRS Abbreviated Journal Proc. MRS
Volume 935 Issue Pages 210 (1 to 6)
Keywords NbN HEB mixers
Abstract (up) Planar spiral antenna coupled and directly lens coupled NbN HEB mixer structures are studied. An additional MgO buffer layer between the superconducting film and Si substrate is introduced. The buffer layer enables us to increase the gain bandwidth of a HEB mixer due to better acoustic transparency. The gain bandwidth is widened as NbN film thickness decreases and amounts to 5.2 GHz. The noise temperature of antenna coupled mixer is 1300 and 3100 K at 2.5 and 3.8 THz respectively. The structure and composition of NbN films is investigated by X-ray diffraction spectroscopy methods. Noise performance degradation at LO frequencies more than 3 THz is due to the use of a planar antenna and signal loss in contacts between the antenna and the sensitive NbN bridge. The mixer is reconfigured for operation at higher frequencies in a manner that receiver’s noise temperature is only 2300 K (3 times of quantum limit) at LO frequency of 30 THz.
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ISSN 0272-9172 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number Serial 1440
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Author Gershenzon, E. M.; Gol'tsman, G. N.; Ptitsina, N. G.
Title Investigation of free excitons in Ge and their condensation at submillimeter wavelengths Type Journal Article
Year 1976 Publication Sov. Phys. JETP Abbreviated Journal Sov. Phys. JETP
Volume 43 Issue 1 Pages 116-122
Keywords Ge, free excitons
Abstract (up) Results are presented of an investigation of free excitons in Ge in the submillimeter wavelength range for low as well as for high excitation levels when interaction between the excitons becomes important. The free-exciton energy spectrum is discussed. It is shown that the drop radii and their concentrations can be determined by measuring the temperature dependence of the free-exciton concentration. A section of the phase diagram is obtained in the 0.5-2.8 K temperature range for the free excitons+condensate system.
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Notes Approved no
Call Number Serial 1731
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Author Tret'yakov, I. V.; Kaurova, N. S.; Voronov, B. M.; Anfert'ev, V. A.; Revin, L. S.; Vaks, V. L.; Gol'tsman, G. N.
Title The influence of the diffusion cooling on the noise band of the superconductor NbN hot-electron bolometer operating in the terahertz range Type Journal Article
Year 2016 Publication Tech. Phys. Lett. Abbreviated Journal
Volume 42 Issue 6 Pages 563-566
Keywords HEB, noise bandwidth, conversion gain bandwidth, noise temperature, Andreev reflection
Abstract (up) Results of an experimental study of the noise temperature (Tn) and noise bandwidth (NBW) of the superconductor NbN hot-electron bolometer (HEB) mixer as a function of its temperature (Tb) are presented. It was determined that the NBW of the mixer is significantly wider at temperatures close to the critical ones (Tc) than are values measured at 4.2 K. The NBW of the mixer measured at the heterodyne frequency of 2.5 THz at temperature Tb close to Tc was ~13 GHz, as compared with 6 GHz at Tb = 4.2 K. This experiment clearly demonstrates the limitation of the thermal flow from the NbN bridge at Tb â‰<aa> Tc for mixers manufactured by the in situ technique. This limitation is close in its nature to the Andreev reflection on the superconductor/ metal boundary. In this case, the noise temperature of the studied mixer increased from 1100 to 3800 K.
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Notes Approved no
Call Number Serial 1106
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Author Smirnov, K. V.; Vakhtomin, Yu. B.; Divochiy, A. V.; Ozhegov, R. V.; Pentin, I. V.; Gol'tsman, G. N.
Title Infrared and terahertz detectors on basis of superconducting nanostructures Type Conference Article
Year 2010 Publication Microwave and Telecom. Technol. (CriMiCo), 20th Int. Crimean Conf. Abbreviated Journal
Volume Issue Pages 823-824
Keywords SSPD, SNSPD, HEB
Abstract (up) Results of development of single-photon receiving systems of visible, infrared and terahertz range based on thin-film superconducting nanostructures are presented. The receiving systems are produced on the basis of superconducting nanostructures, which function by means of hot-electron phenomena.
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Publisher Place of Publication Editor IEEE
Language Summary Language Original Title
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Notes Approved no
Call Number RPLAB @ sasha @ smirnov2010infrared Serial 1025
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Author Kroug, M.; Cherednichenko, S.; Merkel, H.; Kollberg, E.; Voronov, B.; Gol'tsman, G.; Hübers, H. W.; Richter, H.
Title NbN hot electron bolometric mixers for terahertz receivers Type Journal Article
Year 2001 Publication IEEE Trans. Appl. Supercond. Abbreviated Journal IEEE Trans. Appl. Supercond.
Volume 11 Issue 1 Pages 962-965
Keywords NbN HEB mixers
Abstract (up) Sensitivity and gain bandwidth measurements of phonon-cooled NbN superconducting hot-electron bolometer mixers are presented. The best receiver noise temperatures are: 700 K at 1.6 THz and 1100 K at 2.5 THz. Parylene as an antireflection coating on silicon has been investigated and used in the optics of the receiver. The dependence of the mixer gain bandwidth (GBW) on the bias voltage has been measured. Starting from low bias voltages, close to operating conditions yielding the lowest noise temperature, the GBW increases towards higher bias voltages, up to three times the initial value. The highest measured GBW is 9 GHz within the same bias range the noise temperature increases by a factor of two.
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Notes Approved no
Call Number Serial 312
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