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Author Svechnikov, S.; Verevkin, A.; Voronov, B.; Menschikov, E.; Gershenzon, E.; Gol'tsman, G. url  openurl
  Title Quasioptical phonon-cooled NbN hot electron bolometer mixers at 0.5-1.1 THz Type Conference Article
  Year 1998 Publication Proc. 9th Int. Symp. Space Terahertz Technol. Abbreviated Journal Proc. 9th Int. Symp. Space Terahertz Technol.  
  Volume Issue (down) Pages 45-51  
  Keywords NbN HEB mixers  
  Abstract The noise performance of a receiver incorporating spiral antenna coupled NbN phonon-cooled superconducting hot electron bolometric mixer is measured from 450 GHz to 1200 GHz. The mixer element is thin (thickness nm) NbN 1.5 pm wide and 0.2 i.um long film fabricated by lift-off e-beam lithography on high-resistive silicon substrate. The noise of the receiver temperature is 1000 K at 800-900 GHz, 1200 K at 950 GHz, and 1600 K at 1.08 THz. The required (absorbed) local-oscillator power is —20 nW.  
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  Notes Approved no  
  Call Number Serial 1586  
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Author Gousev, Yu. P.; Olsson, H. K.; Gol'tsman, G. N.; Voronov, B. M.; Gershenzon, E. M. url  openurl
  Title NbN hot-electron mixer at radiation frequencies between 0.9 THz and 1.2 THz Type Conference Article
  Year 1998 Publication Proc. 9th Int. Symp. Space Terahertz Technol. Abbreviated Journal Proc. 9th Int. Symp. Space Terahertz Technol.  
  Volume Issue (down) Pages 121-129  
  Keywords NbN HEB mixers  
  Abstract We report on noise temperature measurements for a NbN phonon-cooled hot-electron mixer at radiation frequencies between 0.9 THz and 1.2 THz. Radiation was coupled to the mixer, placed in a vacuum chamber of He cryostat, by means of a planar spiral antenna and a Si immersion lens. A backward-wave oscillator, tunable throughout the spectral range, delivered an output power of few 1.1W that was enough for optimum operation of the mixer. At 4.2 K ambient temperature and 1.025 THz radiation frequency, we obtained a receiver noise temperature of 1550 K despite of using a relatively noisy room-temperature amplifier at the intermediate frequency port. The noise temperature was fairly constant throughout the entire operation range and for intermediate frequencies from 1 GHz to 2 GHz.  
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  Area Expedition Conference  
  Notes Approved no  
  Call Number Serial 1588  
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Author Yazoubov, P.; Kroug, M.; Merkel, H.; Kollberg, E.; Gol'tsman, G.; Lipatov, A.; Svechnikov, S.; Gershenzon, E. url  openurl
  Title Quasioptical NbN phonon-cooled hot electron bolometric mixers with low optimal local oscillator power Type Conference Article
  Year 1998 Publication Proc. 9th Int. Symp. Space Terahertz Technol. Abbreviated Journal Proc. 9th Int. Symp. Space Terahertz Technol.  
  Volume Issue (down) Pages 131-140  
  Keywords NbN HEB mixers  
  Abstract In this paper, the noise perform.ance of NIN based phonon-cooled Hot Electron Bolometric (HEB) quasioptical mixers is investigated in the 0.55-1.1 THz frequency range. The best results of the DSB noise temperature are: 500 K at 640 GHz, 600 K at 750 GHz, 850 K at 910 GHz and 1250 K at 1.1 THz. The water vapor in the signal path causes a significant contribution to the measured noise temperature around 1.1 THz. The required LO power is typically about 60 nW. The frequency response of the spiral antenna+lens system is measured using a Fourier Transform Spectrometer with the HEB operating in a detector mode.  
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  Notes Approved no  
  Call Number Serial 1589  
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Author Karasik, B. S.; Il'in, K. S.; Ptitsina, N. G.; Gol'tsman, G. N.; Gershenzon, E. M.; Pechen', E. V.; Krasnosvobodtsev, S. I. url  openurl
  Title Electron-phonon scattering rate in impure NbC films Type Abstract
  Year 1998 Publication NASA/ADS Abbreviated Journal NASA/ADS  
  Volume Issue (down) Pages Y35.08  
  Keywords NbC films  
  Abstract The study of the electron-phonon interaction in thin (20 nm) NbC films with electron mean free path l=2-13 nm gives an evidence that electron scattering is significantly modified due to the interference between electron-phonon and elastic electron scattering from impurities. The interference ~T^2-term, which is proportional to the residual resistivity, dominates over the Bloch-Grüneisen contribution to resistivity at low temperatures up to 60 K. The electron energy relaxation rate is directly measured via the relaxation of hot electrons heated by modulated electromagnetic radiation. In the temperature range 1.5 – 10 K the relaxation rate shows a weak dependence on the electron mean free path and strong temperature dependence T^n with the exponent n = 2.5-3. This behaviour is well explained by the theory of the electron-phonon-impurity interference taking into account the electron coupling with transverse phonons determined from the resistivity data.  
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  Area Expedition Conference American Physical Society, Annual March Meeting, March 16-20, 1998 Los Angeles, CA  
  Notes Approved no  
  Call Number Serial 1591  
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Author Gerecht, E.; Musante, C. F.; Yngvesson, K. S.; Waldman, J.; Gol'tsman, G. N.; Yagoubov, P. A.; Voronov, B. M.; Gershenzon, E. M. url  openurl
  Title Optical coupling and conversion gain for NbN HEB mixer at THz frequencies Type Conference Article
  Year 1997 Publication Proc. 4-th Int. Semicond. Device Research Symp. Abbreviated Journal Proc. 4-th Int. Semicond. Device Research Symp.  
  Volume Issue (down) Pages 47-50  
  Keywords NbN HEB mixers  
  Abstract  
  Address Charlottesville, Virginia  
  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 Approved no  
  Call Number Serial 1601  
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Author Verevkin, A. A.; Ptitsina, N. G.; Smirnov, K. V.; Gol'tsman, G. N.; Voronov, B. M.; Gershenzon, E. M.; Yngvesson, K. S. url  openurl
  Title Hot electron bolometer detectors and mixers based on a superconducting-two-dimensional electron gas-superconductor structure Type Conference Article
  Year 1997 Publication Proc. 4-th Int. Semicond. Device Research Symp. Abbreviated Journal Proc. 4-th Int. Semicond. Device Research Symp.  
  Volume Issue (down) Pages 163-166  
  Keywords S-2DEG-S HEB mixers, detectors, AlGaAs/GaAs heterostructures, NbN  
  Abstract  
  Address  
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  Area Expedition Conference  
  Notes Approved no  
  Call Number Serial 1603  
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Author Ekström, H.; Kollberg, E.; Yagoubov, P.; Gol'tsman, G.; Gershenzon, E.; Yngvesson, S. url  openurl
  Title Phonon cooled ultra thin NbN hot electron bolometer mixers at 620 GHz Type Conference Article
  Year 1997 Publication Proc. 8th Int. Symp. Space Terahertz Technol. Abbreviated Journal Proc. 8th Int. Symp. Space Terahertz Technol.  
  Volume Issue (down) Pages 29-35  
  Keywords NbN HEB mixers  
  Abstract We have measured the noise performance and gain bandwidth of 35 A thin NbN hot-electron mixers integrated with spiral antennas on silicon substrate lenses at 620 GHz. A double-sideband receiver noise temperature less than 1300 K has been obtained with a 3 dB bandwidth of GHz. The gain bandwidth is 3.2 GHz. A lower noise temperature of 1100 K has been achieved with an improved set-up. The mixer output noise dominated by thermal fluctuations is about 50-60 K, and the SSB receiver and intrinsic conversion gain is about -18 and -12 dB, respectively. Without mismatch losses and excluding the loss from the beamsplitter, we expect to achieve a receiver noise temperature of less than 700 K.  
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  Area Expedition Conference  
  Notes Approved no  
  Call Number Serial 1604  
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Author Gerecht, E.; Musante, C. F.; Wang, Z.; Yngvesson, K. S.; Waldman, J.; Gol'tsman, G. N.; Yagoubov, P. A.; Svechnikov, S. I.; Voronov, B. M.; Cherednichenko, S. I.; Gershenzon, E. M. url  openurl
  Title NbN hot electron bolometric mixer for 2.5 THz: the phonon cooled version Type Conference Article
  Year 1997 Publication Proc. 8th Int. Symp. Space Terahertz Technol. Abbreviated Journal Proc. 8th Int. Symp. Space Terahertz Technol.  
  Volume Issue (down) Pages 258-271  
  Keywords NbN HEB mixers  
  Abstract We describe an investigation of a NbN HEB mixer for 2.5 THz. NbN HEBs are phonon-cooled de-. vices which are expected, according to theory, to achieve up to 10 GHz IF conversion gain bandwidth. We have developed an antenna coupled device using a log-periodic antenna and a silicon lens. We have demon- strated that sufficient LO power can be coupled to the device in order to bring it to the optimum mixer oper- ating point. The LO power required is less than 1 microwatts as measured directly at the device. We also describe the impedance characteristics of NbN devices and compare them with theory. The experimental results agree with theory except for the imaginary part of the impedance at very low frequencies as was demonstrated by other groups.  
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  Corporate Author Thesis  
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  Series Editor Series Title Abbreviated Series Title  
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  Area Expedition Conference  
  Notes Approved no  
  Call Number Serial 1605  
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Author Ekström, H.; Kroug, M.; Belitsky, V.; Kollberg, E.; Olsson, H.; Goltsman, G.; Gershenzon, E.; Yagoubov, P.; Voronov, B.; Yngvesson, S. url  openurl
  Title Hot electron mixers for THz applications Type Conference Article
  Year 1996 Publication Proc. 30th ESLAB Abbreviated Journal Proc. 30th ESLAB  
  Volume Issue (down) Pages 207-210  
  Keywords NbN HEB mixers  
  Abstract We have measured the noise performance of 35 A thin NbN HEB devices integrated with spiral antennas on antireflection coated silicon substrate lenses at 620 GHz. From the noise measurements we have determined a total conversion gain of the receiver of—16 dB, and an intrinsic conversion of about-10 dB. The IF bandwidth of the 35 A thick NbN devices is at least 3 GHz. The DSB receiver noise temperature is less than 1450 K. Without mismatch losses, which is possible to obtain with a shorter device, and with reduced loss from the beamsplitter, we expect to achieve a DSB receiver noise temperature of less ‘than 700 K.  
  Address Noordwijk, Netherlands  
  Corporate Author Thesis  
  Publisher Place of Publication Editor Rolfe, E. J.; Pilbratt, G.  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN ISBN Medium  
  Area Expedition Conference Submillimetre and Far-Infrared Space Instrumentation  
  Notes Approved no  
  Call Number Serial 1606  
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Author Verevkin, A. A.; Ptitsina, N. G.; Chulcova, G. M.; Gol'tsman, G. N.; Gershenzon, E. M.; Yngvesson, K. S. url  doi
openurl 
  Title Direct measurements of energy relaxation time of electrons in AlGaAs/GaAs heterostructures under quasi-equilibrium conditions Type Journal Article
  Year 1996 Publication Surface Science Abbreviated Journal Surface Science  
  Volume 361-362 Issue (down) Pages 569-573  
  Keywords 2DEG, AlGaAs/GaAs heterostructures  
  Abstract For the first time, results are presented of a direct measurement of the energy relaxation time τε of 2D electrons in an AlGaAs/GaAs heterojunction at T = 1 and 5–20 K. A weak temperature dependence of τε for the T > 4K range and a linear temperature dependence of the reciprocal of τε for T < 4K have been observed. The linear dependence τε−1 ≈ T in the Bloch-Gruneisen regime is direct evidence of the predominance of the piezo-electric mechanism of electron-phonon interaction in non-elastic electron scattering processes. The values of τε in this regime are in very good agreement with the results of the Karpus theory. At higher temperatures, where the deformation-potential scattering becomes noticeable, a substantial disagreement between the experimental data and the theoretical results is observed.  
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  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0039-6028 ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number Serial 1609  
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Author Yagoubov, P.; Gol'tsman, G.; Voronov, B.; Svechnikov, S.; Cherednichenko, S.; Gershenzon, E.; Belitsky, V.; Ekström, H.; Semenov, A.; Gousev, Yu.; Renk, K. url  openurl
  Title Quasioptical phonon-cooled NbN hot-electron bolometer mixer at THz frequencies Type Conference Article
  Year 1996 Publication Proc. 7th Int. Symp. Space Terahertz Technol. Abbreviated Journal Proc. 7th Int. Symp. Space Terahertz Technol.  
  Volume Issue (down) Pages 303-317  
  Keywords NbN HEB mixers  
  Abstract In our experiments we tested phonon-cooled hot-electron bolometer (HEB) quasioptical mixer based on spiral antenna designed for 0.5-1.2 THz frequency band and fabricated on sapphire, Si-coated sapphire and high resistivity silicon substrates. HEB devices were produced from thin superconducting NbN film 3.5-6 nm thick with the critical temperature of about 11-12 K. For these devices we achieved the receiver noise temperature T R (DSB) = 3000 K in the 500-700 GHz frequency range and an IF bandwidth of 3-4 GHz. Prelimanary measurements at frequencies 1-1.2 THz resulted the receiver noise temperature about 9000 K (DSB).  
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  Area Expedition Conference  
  Notes Approved no  
  Call Number Serial 1614  
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Author Trifonov, V. A.; Karasik, B. S.; Zorin, M. A.; Gol'tsman, G. N.; Gershenzon, E. M.; Lindgren, M.; Danerud, M.; Winkler, D. url  openurl
  Title 9.6 μm wavelength mixing in a patterned YBa2Cu3O7-δ thin film Type Conference Article
  Year 1996 Publication Proc. 7th Int. Symp. Space Terahertz Technol. Abbreviated Journal Proc. 7th Int. Symp. Space Terahertz Technol.  
  Volume Issue (down) Pages 337-348  
  Keywords YBCO HTS HEB mixers  
  Abstract Hot-electron bolometric (HEB) mixing of 9.6 gm infrared radiation from two lasers in high-quality YBa2Cu307_3 (YBCO) patterned thin film has been demonstrated. A heterodyne measurement showed an intermediate frequency (IF) bandwidth of 18 GHz, limited by our measurement system. An intrinsic limit of 100 GHz is predicted. Between 0.1 and 1 GHz intermediate frequency, temperature fluctuations with an equivalent output noise temperature Tfl up to -150 K, contributed to the mixer noise while Johnson noise dominated above 1 GHz. The overall conversion loss at 77 K at low intermediate frequencies was measured to be -25 dB, of which 13 dB was due to the coupling loss. The IIEB mixer is very promising for use in heterodyne receivers within the whole infrared range.  
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  Area Expedition Conference  
  Notes Approved no  
  Call Number Serial 1615  
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Author Gerecht, E.; Musante, C. F.; Wang, Z.; Yngvesson, K. S.; Mueller, E. R.; Waldman, J.; Gol'tsman, G. N.; Voronov, B. M.; Cherednichenco, S. I.; Svechnikov, S. I.; Yagoubov, P. A.; Gershenzon, E. M. url  openurl
  Title Optimization of hot eleciron bolometer mixing efficiency in NbN at 119 micrometer wavelength Type Conference Article
  Year 1996 Publication Proc. 7th Int. Symp. Space Terahertz Technol. Abbreviated Journal Proc. 7th Int. Symp. Space Terahertz Technol.  
  Volume Issue (down) Pages 584-600  
  Keywords NbN HEB mixers  
  Abstract We describe an investigation of a NbN HEB mixer for 2.5 THz. An intrinsic conversion loss of 23 dB has been measured with a two-laser measurement technique. The conversion loss was limited by the LO power available and is expected to decrease to 10 dB or less when sufficient LO power is available. For this initial experiment we used a prototype device which is directly coupled to the laser beams. We present results for a back-short technique that improves the optical coupling to the device and describe our progress for an antenna-coupled device with a smaller dimension. Based on our measured data for conversion loss and device output noise level, we predict that NbN HEB mixers will be capable of achieving DSB receiver noise temperatures of ten times the quantum noise limit in the THz range.  
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  Notes Approved no  
  Call Number Serial 1616  
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Author Okunev, 0.; Dzardranov, A.; Gol'tsman, G.; Gershenzon, E. url  openurl
  Title Performances of hot—electron superconducting mixer for frequencies less than the gap energy: NbN mixer for 100 GHz operation Type Conference Article
  Year 1995 Publication Proc. 6th Int. Symp. Space Terahertz Technol. Abbreviated Journal Proc. 6th Int. Symp. Space Terahertz Technol.  
  Volume Issue (down) Pages 247-253  
  Keywords NbN HEB mixers  
  Abstract The possibilities to improve the parameters of the 100 GHz NbN HEB superconducting waveguide mixers have been studied. The device consists of a signal strip 1 gm wide by 2 Am long made of 40 A thick NbN film. The best operation point was found at 5 K, where the mixer bandwidth made up 1.5-2 GHz and the total loss diminished down to 8 dB. The critical current density has been increased up to " 40 6 A/cm 2 , the noise temperature of the receiver (DSB) has reduced down to 450 K and the local oscillator power has decreased down to -.4).1 mcV.  
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  Area Expedition Conference  
  Notes Approved no  
  Call Number Serial 1625  
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Author Kawamura, J.; Blundell, R.; Tong, C.-Y. E.; Gol'tsman, G.; Gershenzon, E.; Voronov, B. url  openurl
  Title NbN hot-electron mixer measurements at 200 GHz Type Conference Article
  Year 1995 Publication Proc. 6th Int. Symp. Space Terahertz Technol. Abbreviated Journal Proc. 6th Int. Symp. Space Terahertz Technol.  
  Volume Issue (down) Pages 254-261  
  Keywords NbN HEB mixers  
  Abstract We present noise and gain measurements of resistively driven NbN hot-electron mixers near 200 GHz. The device geometry is chosen so that the dominant cooling process of the hot-electrons is their interaction with the lattice. Except for a single batch, the intermediate frequency cut-off of these mixer elements is – 3 700 MHz, and has shown little variation among other batches of devices. At 100 MHz we measured intrinsic mixer losses as low as —3 dB. We measured the noise temperatures at several intermediate frequencies, and for the best de- vice at 137 MHz with 20 MHz bandwidth, we measured 2000 K; using a low-noise first- stage amplifier at 1.5 GHz with 200 MHz bandwidth, the receiver noise temperature measured 2800 K. We estimate that the noise contribution from the mixer is 500 K and the total losses are —15 dB at 137 MHz.  
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  Area Expedition Conference  
  Notes Approved no  
  Call Number Serial 1626  
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