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De Visser, P.J. (author), Baselmans, J.J.A. (author), Yates, S.J.C. (author), Diener, P. (author), Endo, A. (author), Klapwijk, T.M. (author)We have measured the number of quasiparticles and their lifetime in aluminium superconducting microwave resonators. The number of excess quasiparticles below 160?mK decreases from 72 to 17??m?3 with a 6?dB decrease of the microwave power. The quasiparticle lifetime increases accordingly from 1.4 to 3.5?ms. These properties of the superconductor...journal article 2012
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Endo, A. (author), Van der Werf, P. (author), Janssen, R.M.J. (author), De Visser, P.J. (author), Klapwijk, T.M. (author), Baselmans, J.J.A. (author), Ferrari, L. (author), Baryshev, A.M. (author), Yates, S.J.C. (author)An integrated filterbank (IFB) in combination with microwave kinetic inductance detectors (MKIDs), both based on superconducting resonators, could be used to make broadband submillimeter imaging spectrographs that are compact and flexible. In order to investigate the possibility of adopting an IFB configuration for DESHIMA (Delft SRON High...journal article 2012
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De Visser, P.J. (author), Baselmans, J.J.A. (author), Diener, P. (author), Yates, S.J.C. (author), Endo, A. (author), Klapwijk, T.M. (author)We present measurements of quasiparticle generation-recombination noise in aluminium Microwave Kinetic Inductance Detectors, the fundamental noise source for these detectors. Both the quasiparticle lifetime and the number of quasiparticles can be determined from the noise spectra. The number of quasiparticles saturates to 10 ?m?3 at temperatures...journal article 2012
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Janssen, R.M.J. (author), Endo, A. (author), Baselmans, J.J.A. (author), De Visser, P.J. (author), Barends, R. (author), Klapwijk, T.M. (author)The sensitivity of microwave kinetic inductance detectors (MKIDs) based on coplanar waveguides (CPWs) needs to be improved by at least an order of magnitude to satisfy the requirements for space-based terahertz astronomy. Our aim is to investigate if this can be achieved by reducing the width of the CPW to much below what has typically been made...journal article 2012
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De Visser, P.J. (author), Baselmans, J.J.A. (author), Diener, P. (author), Yates, S.J.C. (author), Endo, A. (author), Klapwijk, T.M. (author)We have directly measured quasiparticle number fluctuations in a thin film superconducting Al resonator in thermal equilibrium. The spectrum of these fluctuations provides a measure of both the density and the lifetime of the quasiparticles. We observe that the quasiparticle density decreases exponentially with decreasing temperature, as...journal article 2011
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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