Searched for: collection%253Air
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Rosticher, M. (author), Ladan, F.R. (author), Maneval, J.P. (author), Dorenbos, S.N. (author), Zijlstra, T. (author), Klapwijk, T.M. (author), Zwiller, V. (author), Lupa?cu, A. (author), Nogues, G. (author)
We report the detection of single electrons using a Nb0.7Ti0.3N superconducting wire deposited on an oxidized silicon substrate. While it is known that this device is sensitive to single photons, we show that it also detects single electrons with kilo-electron-volt energy emitted from the cathode of a scanning electron microscope with an...
journal article 2010
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Zhang, W. (author), Khosropanah, P. (author), Gao, J.R. (author), Bansal, T. (author), Klapwijk, T.M. (author), Miao, W. (author), Shi, S.C. (author)
We report the measured sensitivities of a superconducting NbN hot electron bolometer (HEB) heterodyne receiver at 5.25 THz. Terahertz (THz) radiation is quasioptically coupled to a HEB mixer with a lens and a spiral antenna. Using a measurement setup with black body calibration sources and a beam splitter in vacuo, and an antireflection coated...
journal article 2010
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Dorenbos, S.N. (author), Sasakura, H. (author), Van Kouwen, M.P. (author), Akopian, N. (author), Adachi, S. (author), Namekata, N. (author), Jo, M. (author), Motohisa, J. (author), Kobayashi, Y. (author), Tomioka, K. (author), Fukui, T. (author), Inoue, S. (author), Kumano, H. (author), Natarajan, C.M. (author), Hadfield, R.H. (author), Zijlstra, T. (author), Klapwijk, T.M. (author), Zwiller, V. (author), Suemune, I. (author)
We report the experimental demonstration of single-photon and cascaded photon pair emission in the infrared, originating from a single InAsP quantum dot embedded in a standing InP nanowire. A regular array of nanowires is fabricated by epitaxial growth on an electron-beam patterned substrate. Photoluminescence spectra taken on single quantum...
journal article 2010
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Ren, Y. (author), Hovenier, J.N. (author), Higgins, R. (author), Gao, J.R. (author), Klapwijk, T.M. (author), Shi, S.C. (author), Bell, A. (author), Klein, B. (author), Williams, B.S. (author), Kumar, S. (author), Hu, Q. (author), Reno, J.L. (author)
A terahertz (THz) heterodyne spectrometer is demonstrated based on a quantum cascade laser (QCL) as a local oscillator (LO) and an NbN hot electron bolometer as a mixer, and it is used to measure high-resolution molecular spectral lines of methanol (CH3OH) between 2.913–2.918 THz. The spectral lines are taken from a gas cell containing methanol...
journal article 2010
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Barends, R. (author), Vercruyssen, N. (author), Endo, A. (author), De Visser, P.J. (author), Zijlstra, T. (author), Klapwijk, T.M. (author), Baselmans, J.J.A. (author)
We report a reduction in the frequency noise in coplanar waveguide superconducting resonators. The reduction of 7 dB is achieved by removing the exposed dielectric substrate surface from the region with high electric fields and by using NbTiN. In a model-analysis the surface of NbTiN is found to be a negligible source of noise, experimentally...
journal article 2010
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Barends, R. (author), Vercruyssen, N. (author), Endo, A. (author), De Visser, P.J. (author), Zijlstra, T. (author), Klapwijk, T.M. (author), Diener, P. (author), Yates, S.J.C. (author), Baselmans, J.J.A. (author)
We report quality factors of up to 500x10³ in superconducting resonators at the single photon levels needed for circuit quantum electrodynamics. This result is achieved by using NbTiN and removing the dielectric from regions with high electric fields. As demonstrated by a comparison with Ta, the crucial sources of intensity-dependent loss are...
journal article 2010
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Tanner, M.G. (author), Natarajan, C.M. (author), Pottapenjara, V.K. (author), O'Connor, J.A. (author), Warburton, R.J. (author), Hadfield, R.H. (author), Baek, B. (author), Nam, S. (author), Dorenbos, S.N. (author), Bermúdez Ureña, E. (author), Zijlstra, T. (author), Klapwijk, T.M. (author), Zwiller, V. (author)
Superconducting nanowire single-photon detectors (SNSPDs) have emerged as a highly promising infrared single-photon detector technology. Next-generation devices are being developed with enhanced detection efficiency (DE) at key technological wavelengths via the use of optical cavities. Furthermore, new materials and substrates are being explored...
journal article 2010
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Zhang, W. (author), Khosropanah, P. (author), Gao, J.R. (author), Kollberg, E.L. (author), Yngvesson, K.S. (author), Bansal, T. (author), Barends, R. (author), Klapwijk, T.M. (author)
We have measured the noise temperature of a single, sensitive superconducting NbN hot electron bolometer (HEB) mixer in a frequency range from 1.6 to 5.3 THz, using a setup with all the key components in vacuum. By analyzing the measured receiver noise temperature using a quantum noise (QN) model for HEB mixers, we confirm the effect of QN. The...
journal article 2010
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Barends, R. (author), Van Vliet, S. (author), Baselmans, J.J.A. (author), Yates, S.J.C. (author), Gao, J.R. (author), Klapwijk, T.M. (author)
We present measurements of the quasiparticle relaxation time in Ta superconducting films shaped as planar resonators using the response of the complex conductivity to photon flux. These films have been implanted with magnetic (Mn) as well as non-magnetic atoms (Al). We find a significant decrease of the relaxation time with increasing impurity...
conference paper 2009
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Zhu, S. (author), Zijlstra, T. (author), Golubov, A.A. (author), Van den Bemt, M. (author), Baryshev, A.M. (author), Klapwijk, T.M. (author)
The coupling efficiency of a Nb superconducting transmission line has been measured using a Fourier transform spectrometer for different magnetic fields. It is found that the coupling decreases with increasing magnetic field when the frequency is close to the gap of the Nb superconductor. This is attributed to the changes of the surface...
journal article 2009
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Klapwijk, R. (author), Rommes, E. (author)
In this paper, a new perspective is developed to promote a positive relationship between young people and technology. An in-depth study of the values young Dutch secondary school students feel are essential in their future profession was made. Following organisational psychologist Edgar Schein, we distinguish career anchors, each with their own...
journal article 2009
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Khosropanah, P. (author), Baryshev, A. (author), Zhang, W. (author), Jellema, W. (author), Hovenier, J.N. (author), Gao, J.R. (author), Klapwijk, T.M. (author), Paveliev, D.G. (author), Williams, B.S. (author), Kumar, S. (author), Hu, Q. (author), Reno, J.L. (author), Klein, B. (author), Hesler, J.L. (author)
We demonstrate the phase locking of a 2.7 THz metal–metal waveguide quantum cascade laser (QCL) to an external microwave signal. The reference is the 15th harmonic, generated by a semiconductor superlattice nonlinear device, of a signal at 182 GHz, which itself is generated by a multiplier chain (x12) from a microwave synthesizer at ~15 GHz....
journal article 2009
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Lodewijk, C.F.J. (author), Zijlstra, T. (author), Zhu, S. (author), Mena, F.P. (author), Baryshev, A.M. (author), Klapwijk, T.M. (author)
We study, using niobium-technology, the bandwidth of SIS mixers operating at frequencies close to the energy-gap frequency. Microstriplines of niobium-silicon dioxide-niobium have different properties for the top and bottom superconductor, which we find to depend on the used fabrication process. Replacing the AlOx tunnel barrier by AlN, the...
journal article 2009
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Barends, R. (author), Hortensius, H.L. (author), Zijlstra, T. (author), Baselmans, J.J.A. (author), Yates, S.J.C. (author), Gao, J.R. (author), Klapwijk, T.M. (author)
We present measurements of the frequency noise and resonance frequency temperature dependence in planar superconducting resonators on both silicon and sapphire substrates. We show, by covering the resonators with sputtered SiOx layers of different thicknesses, that the temperature dependence of the resonance frequency scales linearly with...
journal article 2009
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Barends, R. (author), Van Vliet, S. (author), Baselmans, J.J.A. (author), Yates, S.J.C. (author), Gao, J.R. (author), Klapwijk, T.M. (author)
The quasiparticle recombination time in superconducting films, consisting of the standard electron-phonon interaction and a yet to be identified low-temperature process, is studied for different densities of magnetic and nonmagnetic atoms. For both Ta and Al, implanted with Mn, Ta, and Al, we observe an increase in the recombination rate. We...
journal article 2009
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Khosropanah, P. (author), Zhang, W. (author), Hovenier, J.N. (author), Gao, J.R. (author), Klapwijk, T.M. (author), Amanti, M.I. (author), Scalari, G. (author), Faist, J. (author)
We report a heterodyne receiver using a superconducting NbN hot electron bolometer (HEB) integrated with a tight winding spiral antenna as mixer and a distributed feedback (DFB) terahertz quantum cascade laser (QCL) operating at 3.42 THz as local oscillator. The aim is to demonstrate the readiness of both devices for the detection of OH lines at...
journal article 2008
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Khosropanah, P. (author), Laauwen, W.M. (author), Hajenius, M. (author), Gao, J.R. (author), Klapwijk, T.M. (author)
We have studied the sensitivity of a superconducting NbN hot electron bolometer mixer integrated with a spiral antenna at 4.3 THz. Using hot/cold blackbody loads and a beam splitter all in vacuum, we measured a double sideband receiver noise temperature of 1300 K at the optimum local oscillator (LO) power of 330 nW, which is about 12 times the...
conference paper 2008
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Smith, H. (author), Buckle, J. (author), Hills, R. (author), Bell, G. (author), Richer, J. (author), Curtis, E. (author), Withington, S. (author), Leech, J. (author), Williamson, R. (author), Klapwijk, T.M. (author)
This paper describes the key design features and performance of HARP, an innovative heterodyne focal-plane array receiver designed and built to operate in the submillimetre on the James Clerk Maxwell Telescope (JCMT) in Hawaii. The 4x4 element array uses SIS detectors, and is the first sub-millimetre spectral imaging system on the JCMT. HARP...
conference paper 2008
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De Graauw, T. (author), Whyborn, N. (author), Helmich, F. (author), Dieleman, P. (author), Roelfsema, P. (author), Caux, E. (author), Phillips, T. (author), Stutzki, J. (author), Beintema, D. (author), Klapwijk, T. (author)
This paper describes the Heterodyne Instrument for the Far-Infrared (HIFI), to be launched onboard of ESA's Herschel Space Observatory, by 2008. It includes the first results from the instrument level tests. The instrument is designed to be electronically tuneable over a wide and continuous frequency range in the Far Infrared, with velocity...
conference paper 2008
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Barends, R. (author), Baselmans, J.J.A. (author), Yates, S.J.C. (author), Gao, J.R. (author), Hovenier, J.N. (author), Klapwijk, T.M. (author)
The quasiparticle relaxation time in superconducting films has been measured as a function of temperature using the response of the complex conductivity to photon flux. For tantalum and aluminum, chosen for their difference in electron-phonon coupling strength, we find that at high temperatures the relaxation time increases with decreasing...
journal article 2008
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