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Author Kroug, M.; Cherednichenko, S.; Choumas, M.; Merkel, H.; Kollberg, E.; Hübers, H.-W.; Richter, H.; Loudkov, D.; Voronov, B.; Gol'Tsman, G.
Title HEB quasi-optical heterodyne receiver for THz frequencies Type Conference Article
Year 2001 Publication Proc. 12th Int. Symp. Space Terahertz Technol. Abbreviated Journal
Volume Issue Pages (up) 244-252
Keywords HEB mixer, NbN, MgO, conversion gain bandwidth, noise temperature
Abstract
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Corporate Author Thesis
Publisher Place of Publication San Diego, CA, USA Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
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ISSN ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number Serial 319
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Author Cherednichenko, S.; Yagoubov, P.; Il'In, K.; Gol'tsman, G.; Gershenzon, E.
Title Large bandwidth of NbN phonon-cooled hot-electron bolometer mixers on sapphire substrates Type Conference Article
Year 1997 Publication Proc. 8th Int. Symp. Space Terahertz Technol. Abbreviated Journal Proc. 8th Int. Symp. Space Terahertz Technol.
Volume Issue Pages (up) 245-257
Keywords NbN HEB mixers, fabrication process
Abstract The bandwidth of NbN phonon-cooled hot electron bolometer mixers has been systematically investigated with respect to the film thickness and film quality variation. The films, 2.5 to 10 mm thick, were fabricated on sapphire substrates using DC reactive magnetron sputtering. All devices consisted of several parallel strips, each 1 1.1 wide and 211 long, placed between Ti-Au contact pads. To measure the gain bandwidth we used two identical BWOs operating in the 120-140 GHz frequency range, one functioning as a local oscillator and the other as a signal source. The majority of the measurements were made at an ambient temperature of 4.5 K with optimal LO and DC bias. The maximum 3 dB bandwidth (about 4 GHz) was achieved for the devices made of films which were 2.5-3.5 nm thick, had a high critical temperature, and high critical current density. A theoretical analysis of bandwidth for these mixers based on the two-temperature model gives a good description of the experimental results if one assumes that the electron temperature is equal to the critical temperature.
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Area Expedition Conference
Notes Approved no
Call Number Serial 276
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Author Gol'tsman, G.; Minaeva, O.; Korneev, A.; Tarkhov, M.; Rubtsova, I.; Divochiy, A.; Milostnaya, I.; Chulkova, G.; Kaurova, N.; Voronov, B.; Pan, D.; Kitaygorsky, J.; Cross, A.; Pearlman, A.; Komissarov, I.; Slysz, W.; Wegrzecki, M.; Grabiec, P.; Sobolewski, R.
Title Middle-infrared to visible-light ultrafast superconducting single-photon detectors Type Journal Article
Year 2007 Publication IEEE Trans. Appl. Supercond. Abbreviated Journal IEEE Trans. Appl. Supercond.
Volume 17 Issue 2 Pages (up) 246-251
Keywords SSPD, SNSPD
Abstract We present an overview of the state-of-the-art of NbN superconducting single-photon detectors (SSPDs). Our devices exhibit quantum efficiency (QE) of up to 30% in near-infrared wavelength and 0.4% at 5 mum, with a dark-count rate that can be as low as 10 -4 s -1 . The SSPD structures integrated with lambda/4 microcavities achieve a QE of 60% at telecommunication, 1550-nm wavelength. We have also developed a new generation of SSPDs that possess the QE of large-active-area devices, but, simultaneously, are characterized by low kinetic inductance that allows achieving short response times and the GHz-counting rate with picosecond timing jitter. The improvements presented in the SSPD development, such as fiber-coupled SSPDs, make our detectors most attractive for high-speed quantum communications and quantum computing.
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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 1051-8223 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number Serial 431
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Author Okunev, 0.; Dzardranov, A.; Gol'tsman, G.; Gershenzon, E.
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 Pages (up) 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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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 1625
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Author Kawamura, J.; Blundell, R.; Tong, C.-Y. E.; Gol'tsman, G.; Gershenzon, E.; Voronov, B.
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 Pages (up) 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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Series Editor Series Title Abbreviated Series Title
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Notes Approved no
Call Number Serial 1626
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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.
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 Pages (up) 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
Publisher Place of Publication Editor
Language Summary Language Original Title
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 Bell, M.; Kaurova, N.; Divochiy, A.; Gol'tsman, G.; Bird, J.; Sergeev, A.; Verevkin, A.
Title On the nature of resistive transition in disordered superconducting nanowires Type Journal Article
Year 2007 Publication IEEE Trans. Appl. Supercond. Abbreviated Journal IEEE Trans. Appl. Supercond.
Volume 17 Issue 2 Pages (up) 267-270
Keywords SSPD, SNSPD
Abstract Hot-electron single-photon counters based on long superconducting nanowires are starting to become popular in optical and infrared technologies due to their ultimately high sensitivity and very high response speed. We investigate intrinsic fluctuations in long NbN nanowires in the temperature range of 4.2 K-20 K, i.e. above and below the superconducting transition. These fluctuations are responsible for fluctuation resistivity and also determine the noise in practical devices. Measurements of the fluctuation resistivity were performed at low current densities and also in external magnetic fields up to 5 T. Above the BCS critical temperature T co the resistivity is well described by the Aslamazov-Larkin (AL) theory for two-dimensional samples. Below T co the measured resistivity is in excellent agreement with the Langer-Ambegaokar-McCumber-Halperin (LAMH) theory developed for one-dimensional superconductors. Despite that our nanowires of 100 nm width are two-dimensional with respect to the coherence length, our analysis shows that at relatively low current densities the one-dimensional LAMH mechanism based on thermally induced phase slip centers dominates over the two-dimensional mechanism related to unbinding of vortex-antivortex pairs below the Berezinskii-Kosterlitz-Thouless transition.
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 1051-8223 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number Serial 1247
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Author Gol'tsman, G. N.; Karasik, B. S.; Svechnikov, S. I.; Gershenzon, E. M.; Ekström, H.; Kollberg E.
Title Noise temperature of NbN hot—electron quasioptical superconducting mixer in 200-700 GHz range Type Abstract
Year 1995 Publication Proc. 6th Int. Symp. Space Terahertz Technol. Abbreviated Journal Proc. 6th Int. Symp. Space Terahertz Technol.
Volume Issue Pages (up) 268
Keywords NbN HEB mixers, noise temperature
Abstract The electron heating effect in superconducting films is becoming very attractive for the development of THz range mixers because of the absence of frequency limitations inherent in the bolometric mechanism. However, the evidence for the spectral dependence of the position of optimal operating point has been found recently for NbN thin film devices 1.2 • The effect is presumably attributed to the variation in the absorption of radiation depending on the frequency. Since the resistive state is not spatially uniform the coupling efficiency of the mixer device with radiation can be different for frequencies larger than Zeilh and those smaller than 2Alh (d is the effective superconducting gap in the resistive state). To study the effect more thoroughly we have investigated the noise temperature of quasioptical NbN mixer device with broken hue tapered slot antenna in the frequency range 200-700 GHz. The device consists of several (5-10) parallel strips 1 jim wide and 6-7 tun thick made from NbN film on Si0 2 -Si 3 N 4 -Si membrane. The strips are connected with the gold contacts of the slot-line antenna which serves both as bias and IF leads. We used backward wave oscillators as LO sources and a standard hot/cold load technique for noise temperature measurements. The frequency dependence of noise temperature is mainly determined by two factors: frequency properties of the antenna and frequency dependence of the NbN film impedance. To separate both factors we monitored the frequency dependence of the device responsivity in the detector mode at a higher temperature within the superconducting transition where the impedance of NbN film is close to its normal resistance. In this case the impedance of the device itself is frequency independent. The experimental results will be reported at the Symposium. 1. G. Gollsman, S. Jacobsson, H. EkstrOm, B. Karasik, E. Kollberg, and E. Gershenzon, “Slot-line tapered antenna with NbN hot electron mixer for 300-360 GHz operation,” Proc of the 5th Int. Symp. on Space Terahertz Technology, pp. 209-213a, May 10-12,1994. 2. B.S. Karasik, G.N. Gol i tsman, B.M. Voronov, S.I. Svechnikov, E.M. Gershenzon, H. Ekstrom, S. Jacobsson, E. Kollberg, and K.S. Yngvesson, “Hot electron quasioptical NbN superconducting mixer,” presented at the ASC94, submitted to IEEE Trans. on Appl. Superconductivity.
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Notes Approved no
Call Number Serial 1627
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Author Gershenzon, E.; Gershenzon, M. E.; Gol'tsman, G. N.; Semenov, A. D.; Sergeev, A. V.
Title Heating of quasiparticles in a superconducting film in the resistive state Type Journal Article
Year 1981 Publication JETP Lett. Abbreviated Journal JETP Lett.
Volume 34 Issue 5 Pages (up) 268-271
Keywords
Abstract
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Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
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Area Expedition Conference
Notes Approved no
Call Number Serial 1716
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Author Ekström, H.; Karasik, B.; Kollberg, E.; Gol'tsman, G.; Gershenzon, E.
Title 350 GHz NbN hot electron bolometer mixer Type Conference Article
Year 1995 Publication Proc. 6th Int. Symp. Space Terahertz Technol. Abbreviated Journal Proc. 6th Int. Symp. Space Terahertz Technol.
Volume Issue Pages (up) 269-283
Keywords NbN HEB mixers
Abstract Superconducting NbN hot-electron bolometer (HEB) mixer devices have been fabricated and measured at 350 GHz. The HEB is integrated with a double dipole antenna on an extended crystalline quartz hyper hemispherical substrate lens. Heterodyne measurement gave a -3 dB bandwidth, mainly determined by the electron- phonon interaction time, of about 680 and 1000 MHz for two different films with Tc = 8.5 and 11 K respectively. The measured DSB receiver noise temperature is around 3000 K at 800 MHz IF frequency. The main contribution to the output noise from the device is due to electron temperature fluctuations with the equivalent output noise temperature TFL-100 K. TH, has the same frequency dependence as the IF response. The contribution from Johnson noise is of the order of T. The RF coupling loss is estimated to be = 6 dB. The film with lower Tc, had an estimated intrinsic low-frequency conversion loss = 7 dB, while the other film had a conversion loss as high as 14 dB. The difference in intrinsic conversion loss is explained by less uniform absorption of radiation. Measurements of the small signal impedance shows a transition of the output impedance from the DC differential resistance Rd=dV/dI in the low frequency limit to the DC resistance R 0 =Uoff 0 in the bias point for frequencies above 3 GHz. We judge that the optimum shape of the IV-characteristic is more easily obtained at THz frequencies where the main restriction in performance should come from problems with the RF coupling.
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Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
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Area Expedition Conference
Notes Approved no
Call Number Serial 1628
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