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Gao, J.R. (author), Hajenius, M. (author), Tichelaar, F.D. (author), Klapwijk, T.M. (author), Voronov, B. (author), Grishin, E. (author), Gol'tsman, G. (author), Zorman, C.A. (author), Mehregany, M. (author)The authors have realized NbN (100) nanofilms on a 3C-SiC (100)/Si(100) substrate by dc reactive magnetron sputtering at 800?°C. High-resolution transmission electron microscopy (HRTEM) is used to characterize the films, showing a monocrystalline structure and confirming epitaxial growth on the 3C-SiC layer. A film ranging in thickness from 3.4...journal article 2007
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Goennenwein, S.T.B. (author), Schink, S.W. (author), Brandlmaier, A. (author), Boger, A. (author), Opel, M. (author), Gross, R. (author), Keizer, R.S. (author), Klapwijk, T.M. (author), Gupta, A. (author), Huebl, H. (author), Bihler, C. (author), Brandt, M.S. (author)We study the magnetoresistance properties of thin ferromagnetic CrO2 and Fe3O4 films under microwave irradiation. Both the sheet resistance ? and the Hall voltage VHall characteristically change when a ferromagnetic resonance (FMR) occurs in the film. The electrically detected ferromagnetic resonance (EDFMR) signals closely match the...journal article 2007
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Goennenwein, S.T.B. (author), Keizer, R.S. (author), Schink, S.W. (author), Van Dijk, I. (author), Klapwijk, T.M. (author), Miao, G.X. (author), Xiao, G. (author), Gupta, A. (author)We have measured the in-plane anisotropic magnetoresistance of 100?nm thick CrO2 thin films at liquid He temperatures. In low magnetic fields H, both the longitudinal and the transverse (planar Hall) resistance show abrupt switches, which characteristically depend on the orientation of H. All the experimental findings consistently demonstrate...journal article 2007
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Kooi, J.W. (author), Baselmans, J.J.A. (author), Hajenius, M. (author), Gao, J.R. (author), Klapwijk, T.M. (author), Dieleman, P. (author), Baryshev, A. (author), De Lange, G. (author)The intermediate frequency (IF) characteristics, the frequency dependent IF impedance, and the mixer conversion gain of a small area hot electron bolometer (HEB) have been measured and modeled. The device used is a twin slot antenna coupled NbN HEB mixer with a bridge area of 1×0.15??m2, and a critical temperature of 8.3?K. In the experiment the...journal article 2007
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- Russo, S. (author), Tobiska, J. (author), Klapwijk, T.M. (author), Morpurgo, A.F. (author) journal article 2007
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- Russo, S. (author), Klapwijk, T.M. (author), Schoch, W. (author), Limmer, W. (author) journal article 2007
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Baselmans, J.J.A. (author), Baryshev, A. (author), Reker, S.F. (author), Hajenius, M. (author), Gao, J.R. (author), Klapwijk, T.M. (author), Voronov, B. (author), Gol'tsman, G. (author)We present a detailed experimental study of the direct detection effect in a small volume (0.15??m×1??m×3.5?nm) quasioptical NbN phonon cooled hot electron bolometer mixer at 673?GHz. We find that the small signal noise temperature, relevant for an astronomical observation, is 20% lower than the noise temperature obtained using 300 and 77?K...journal article 2006
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Hajenius, M. (author), Baselmans, J.J.A. (author), Baryshev, A. (author), Gao, J.R. (author), Klapwijk, T.M. (author), Kooi, J.W. (author), Jellema, W. (author), Yang, Z.Q. (author)We present a complete experimental characterization of a quasioptical twin-slot antenna coupled small area (1.0×0.15??m2) NbN hot electron bolometer (HEB) mixer compatible with currently available solid state tunable local oscillator (LO) sources. The required LO power absorbed in the HEB is analyzed in detail and equals only 25?nW. Due to the...journal article 2006
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Kooi, J.W. (author), Baselmans, J.J.A. (author), Baryshev, A. (author), Schieder, R. (author), Hajenius, M. (author), Gao, J.R. (author), Klapwijk, T.M. (author), Voronov, B. (author), Gol'tsman, G. (author)In this paper we discuss the stability of heterodyne terahertz receivers based on small volume NbN phonon cooled hot electron bolometers (HEBs). The stability of these receivers can be broken down in two parts: the intrinsic stability of the HEB mixer and the stability of the local oscillator (LO) signal injection scheme. Measurements show that...journal article 2006
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Kasemann, C. (author), Güsten, R. (author), Heyminck, S. (author), Klein, B. (author), Klein, T. (author), Philipp, S.D. (author), Korn, A. (author), Schneider, G. (author), Henseler, A. (author), Baryshev, A. (author), Klapwijk, T.M. (author)CHAMP+, a dual-color 2 × 7 element heterodyne array for operation in the 450 ?m and 350 ?m atmospheric windows is under development. The instrument, which is currently undergoing final evaluation in the laboratories, will be deployed for commissioning at the APEX telescope in August this year. With its state-of-the-art SIS detectors and wide...conference paper 2006
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De Lange, G. (author), Jackson, B.D. (author), Jochemsen, M. (author), Laauwen, W.M. (author), De Jong, L. (author), Kroug, M. (author), Zijlstra, T. (author), Klapwijk, T.M. (author)We describe the performance of the Band 3 and Band 4 Flight Model mixer units for Herschel/HIFI Instrument. These units are part of the Focal Plane Unit of HIFI. The band 3 and 4 mixer units cover the 800-960 GHz and 960-1120 GHz frequency range and have a 4-8 GHz IF frequency band. The sensitivities of the mixers within the HIFI setting are...conference paper 2006
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- Keizer, R.S. (author), Flokstra, M.G. (author), Aarts, J. (author), Klapwijk, T.M. (author) journal article 2006
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- Shashkin, A.A. (author), Anissimova, S. (author), Sakr, M.R. (author), Kravchenko, S.V. (author), Dolgopolov, V.T. (author), Klapwijk, T.M. (author) journal article 2006
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- Shashkin, A.A. (author), Deviatov, E.V. (author), Dolgopolov, V.T. (author), Kapustin, A.A. (author), Anissimova, S. (author), Venkatesan, A. (author), Kravchenko, S.V. (author), Klapwijk, T.M. (author) journal article 2006
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- Orlova, E.E. (author), Hovenier, J.N. (author), Klaassen, T.O. (author), Kasalynas, I. (author), Adam, A.J.L. (author), Gao, J.R. (author), Klapwijk, T.M. (author), Williams, B.S. (author), Kumar, S. (author), Hu, Q. (author), Reno, J.L. (author) journal article 2006
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- Anissimova, S. (author), Venkatesan, A. (author), Shashkin, A.A. (author), Sakr, M.R. (author), Kravchenko, S.V. (author), Klapwijk, T.M. (author) journal article 2006
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Barends, R. (author), Hajenius, M. (author), Gao, J.R. (author), Klapwijk, T.M. (author)We present a description of the current-voltage characteristics of hot electron bolometers in terms of the current-dependent intrinsic resistive transition of NbN films. We find that, by including this current dependence, we can correctly predict the complete current-voltage characteristics, showing excellent agreement with measurements for both...journal article 2005
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- Craciun, M.F. (author), Rogge, S. (author), Klapwijk, T.M. (author), Morpurgo, A. (author) patent 2005
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Gao, J.R. (author), Hovenier, J.N. (author), Yang, Z.Q. (author), Baselmans, J.J.A. (author), Baryshev, A. (author), Hajenius, M. (author), Klapwijk, T.M. (author), Adam, A.J.L. (author), Klaassen, T.O. (author), Williams, B.S. (author), Kumar, S. (author), Hu, Q. (author), Reno, J.L. (author)We report the first demonstration of an all solid-state heterodyne receiver that can be used for high-resolution spectroscopy above 2?THz suitable for space-based observatories. The receiver uses a NbN superconducting hot-electron bolometer as mixer and a quantum cascade laser operating at 2.8?THz as local oscillator. We measure a double...journal article 2005
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Jackson, B.D. (author), De Lange, G. (author), Zijlstra, T. (author), Kroug, M. (author), Klapwijk, T.M. (author), Stern, J.A. (author)Integrating NbTiN-based microstrip tuning circuits with traditional Nb superconductor-insulator-superconductor (SIS) junctions enables the low-noise operation regime of SIS mixers to be extended from below 0.7?to?1.15?THz. In particular, mixers incorporating a NbTiN/SiO2/NbTiN microstrip tuning circuit offer low-noise performance below 0.8–0.85...journal article 2005