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Author Tretyakov, I. V.; Ryabchun, S. A.; Maslennikov, S. N.; Finkel, M. I.; Kaurova, N. S.; Seleznev, V. A.; Voronov, B. M.; Gol'tsman, G.N.
Title NbN HEB mixer: fabrication, noise temperature reduction and characterization Type Conference Article
Year 2008 Publication Proc. Basic problems of superconductivity Abbreviated Journal
Volume Issue Pages (up)
Keywords HEB, mixer, noise temperature, conversion gain bandwidth
Abstract We demonstrate that in the terahertz region superconducting hot-electron mixers offer the lowest noise temperature, opening the possibility of using HTS's in the future to fabricate these devices. Specifically, a noise temperature of 950 K was measured for the receiver operating at 2.5 THz with a NbN HEB mixer, and a gain bandwidth of 6 GHz was measured at 300 GHz near Tc for the same mixer.
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Corporate Author Thesis
Publisher Place of Publication Moscow-Zvenigorod 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 591
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Author Finkel, M.; Thierschmann, H. R.; Galatro, L.; Katan, A. J.; Thoen, D. J.; de Visser, P. J.; Spirito, M.; Klapwijk, T. M.
Title Branchline and directional THz coupler based on PECVD SiNx-technology Type Conference Article
Year 2016 Publication 41st IRMMW-THz Abbreviated Journal 41st IRMMW-THz
Volume Issue Pages (up)
Keywords microstrip, fixtures, coplanar waveguides, couplers, standards, probes, dielectrics
Abstract A fabrication technology to realize THz microstrip lines and passive circuit components is developed and tested making use of a plasma-enhanced chemical vapor deposition grown silicon nitride (PECVD SiNx) dielectric membrane. We use 2 μm thick SiNx and 300 nm thick gold layers on sapphire substrates. We fabricate a set of structures for thru-reflect-line (TRL) calibration, with the reflection standard implemented as a short through the via. We find losses of 9.5 dB/mm at 300 GHz for a 50 Ohm line. For a branchline coupler we measure 2.5 dB insertion loss, 1 dB amplitude imbalance and 21 dB isolation. Good control over the THz lines parameters is proven by similar performance of a set of 5 structures. The directional couplers show -14 dB transmission to the coupled port, -24 dB to the isolated port and -25 dB in reflection. The SiNx membrane, used as a dielectric, is compatible with atomic force microscopy (AFM) cantilevers allowing the application of this technology to the development of a THz near-field microscope.
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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 2162-2035 ISBN 978-1-4673-8485-8 Medium
Area Expedition Conference
Notes Approved no
Call Number 7758586 Serial 1295
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Author Goltsman, G. N.; Korneev, A. A.; Finkel, M. I.; Divochiy, A. V.; Florya, I. N.; Korneeva, Y. P.; Tarkhov, M. A.; Ryabchun, S. A.; Tretyakov, I. V.; Maslennikov, S. N.; Kaurova, N. S.; Chulkova, G. M.; Voronov, B. M.
Title Superconducting hot-electron bolometer as THz mixer, direct detector and IR single-photon counter Type Abstract
Year 2010 Publication 35th Int. Conf. Infrared, Millimeter, and Terahertz Waves Abbreviated Journal
Volume Issue Pages (up) 1-1
Keywords SSPD, SNSPD, HEB
Abstract We present a new generation of superconducting single-photon detectors (SSPDs) and hot-electron superconducting sensors with record characteristic for many terahertz and optical applications.
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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 2162-2027 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number RPLAB @ sasha @ goltsman2010superconducting Serial 1028
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Author Kardakova, A. I.; Coumou, P. C. J. J.; Finkel, M. I.; Morozov, D. V.; An, P. P.; Goltsman, G. N.; Klapwijk, T. M.
Title Electron–phonon energy relaxation time in thin strongly disordered titanium nitride films Type Journal Article
Year 2015 Publication IEEE Trans. Appl. Supercond. Abbreviated Journal IEEE Trans. Appl. Supercond.
Volume 25 Issue 3 Pages (up) 1-4
Keywords TiN MKID
Abstract We have measured the energy relaxation times from the electron bath to the phonon bath in strongly disordered TiN films grown by atomic layer deposition. The measured values of τ eph vary from 12 to 91 ns. Over a temperature range from 3.4 to 1.7 K, they follow T -3 temperature dependence, which are consistent with values of τ eph reported previously for sputtered TiN films. For the most disordered film, with an effective elastic mean free path of 0.35 nm, we find a faster relaxation and a stronger temperature dependence, which may be an additional indication of the influence of strong disorder on a superconductor.
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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 1296
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Author Tretyakov, I.; Maslennikov, S.; Semenov, A.; Safir, O.; Finkel, M.; Ryabchun, S.; Kaurova, N.; Voronov, B.; Goltsman, G.; Klapwijk, T. M.
Title Impact of operating conditions on noise and gain bandwidth of NbN HEB mixers Type Conference Article
Year 2015 Publication Proc. 26th Int. Symp. Space Terahertz Technol. Abbreviated Journal Proc. 26th Int. Symp. Space Terahertz Technol.
Volume Issue Pages (up) 39
Keywords NbN HEB mixers
Abstract Hot-electron bolometer mixers (HEB’s) are the most promising devices as mixing element for terahertz spectroscopy and astronomy at frequencies beyond 1.4 THz. They have a low noise temperature and low demands on local oscillator (LO) power. 1,2 An important limitation is the IF bandwidth, of the order of a few GHz, and which in principle depends on energy relaxation due to electron- phonon processes and on diffusion-cooling. It has been proposed by Prober that a reduction in length of the HEB would lead to an increased bandwidth. 3 This appeared to be achieved by Tretyakov et al by measuring the gain bandwidth close to the critical temperature of the NbN. 2 Unfortunately, the noise bandwidth of similar devices operated at temperatures around 4.2 K appear not depend on the length. The fundamental problem to be addressed is the position-dependent superconducting state of the HEB- devices under operating conditions, which determines the conditions for the cooling of the hot quasiparticles. Some progress has been made by Barends et al in a semi-empirical model to describe the I,V curves under operating conditions at a bath temperature around 4.2 K. 4 In more recent work Vercruyssen et al have analyzed the I,V curve, without any LO-equivalent bias, of a model NSN system. 5 This work suggests that the most appropriate model for an HEB under operating conditions is that of a potential-well in the superconducting gap in the center of the NbN, analogous the bimodal superconducting state described by Vercruyssen et al. Hot quasiparticles in the well can not diffuse out and can only cool by electron-phonon processes, those with higher energies than the heights of the walls of the well can diffuse out. Using this working hypothesis we have carried out experiments on a sub-micrometer NbN bridge connected to a gold (Au) planar spiral antenna. An in situ process is used to deposit Au on NbN. The Au is removed in the center to define the uncovered NbN, which will act as the superconducting mixer itself. The antenna is deposited on the remaining Au layer on the NbN. The Au contacts suppress the energy gap of the NbN film located underneath the gold layer 7,8 . The measured resistive transition is shown in Fig.1. It clearly shows a T c of the bilayer at 6.2 K and the resistive transition of the NbN itself around 9 K. In addition we show the measured noise bandwidth (red squares) for different bath temperatures. Clearly the noise bandwidth increases strongly by increasing the bath temperature from 5 K to 8 K, up to 13 GHz. We interpret this pattern as evidence for improved out-diffusion of hot electrons due to normal banks and a shallow superconducting potential well compared to k B T. As expected the noise temperature in this regime is much bigger than when biased at 4.2 K. R EFERENCES 1 W. Zhang, P. Khosropanah, J. R. Gao, E. L. Kollberg, K. S. Yngvesson, T. Bansal, R. Barends, and T. M. Klapwijk Appl. Phys. Lett. 96, 111113, (2010). 2 Ivan Tretyakov, Sergey Ryabchun, Matvey Finkel, Anna Maslennikova, Natalia Kaurova, Anastasia Lobastova, Boris Voronov, and Gregory Gol’tsman Appl. Phys. Lett. 98, 033507 (2011). 3 D. E. Prober, Appl. Phys. Lett. 62, 2119 (1992). 4 R. Barends, M. Hajenius, J. R. Gao, and T. M. Klapwijk, Appl. Phys. Lett. 87, 263506 (2005). 5 N. Vercruyssen, T. G. A. Verhagen, M. G. Flokstra, J. P. Pekola, and T. M. Klapwijk Physical Review B 85, 224503 (2012).
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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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Notes Approved no
Call Number Serial 1159
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