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Quasiparticle relaxation in high Q superconducting resonators

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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Doubling of sensitivity and bandwidth in phonon cooled hot electron bolometer mixers

Baselmans, J. (author), Hajenius, M. (author), Gao, J. (author), De Korte, P. (author), Klapwijk, T. (author), Voronov, B. (author), Gol'tsman, G. (author)

NbN hot electron bolometer (HEB) mixers are at this moment the best heterodyne detectors for frequencies above 1 THz. However, the fabrication procedure of these devices is such that the quality of the interface between the NbN superconducting film and the contact structure is not under good control. This results in a contact resistance between...

conference paper 2004

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Improved superconducting hot-electron bolometer devices for the THz range

Klapwijk, T.M. (author), Barends, R. (author), Gao, J.R. (author), Hajenius, M. (author), Baselmans, J.J.A. (author)

Improved and reproducible heterodyne mixing (noise temperatures of 950 K at 2.5 THz) has been realized with NbN based hot-electron superconducting devices with low contact resistances. A distributed temperature numerical model of the NbN bridge, based on a local electron and a phonon temperature, has been used to understand the physical...

conference paper 2004

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The non-equilibrium response of a superconductor to pair-breaking radiation measured over a broad frequency band

De Visser, P.J. (author), Yates, S.J.C. (author), Guruswamy, T. (author), Goldie, D.J. (author), Withington, S. (author), Neto, A. (author), Llombart, N. (author), Baryshev, A.M. (author), Klapwijk, T.M. (author), Baselmans, J.J.A. (author)

We have measured the absorption of terahertz radiation in a BCS superconductor over a broad range of frequencies from 200 GHz to 1.1 THz, using a broadband antenna-lens system and a tantalum microwave resonator. From low frequencies, the response of the resonator rises rapidly to a maximum at the gap edge of the superconductor. From there on,...

journal article 2015

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Power handling and responsivity of submicron wide superconducting coplanar waveguide resonators

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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High optical efficiency and photon noise limited sensitivity of microwave kinetic inductance detectors using phase readout

Janssen, R.M.J. (author), Baselmans, J.J.A. (author), Endo, A. (author), Ferrari, L. (author), Yates, S.J.C. (author), Baryshev, A.M. (author), Klapwijk, T.M. (author)

We demonstrate photon noise limited performance in both phase and amplitude readout in microwave kinetic inductance detectors (MKIDs) consisting of NbTiN and Al, down to 100 fW of optical power. We simulate the far field beam pattern of the lens-antenna system used to couple radiation into the MKID and derive an aperture efficiency of 75%. This...

journal article 2013

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Nonequilibrium supercurrent transport in controllable superconductor-normal-metal-superconductor junctions

Baselmans, J.J.A. (author), van Wees, B.J. (author), Klapwijk, T.M. (author)

journal article 2001

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Reduced frequency noise in superconducting resonators

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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IF impedance and mixer gain of NbN hot electron bolometers

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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Stability of heterodyne terahertz receivers

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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Terahertz heterodyne receiver based on a quantum cascade laser and a superconducting bolometer

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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Contribution of dielectrics to frequency and noise of NbTiN superconducting resonators

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 study NbTiN resonators by measurements of the temperature dependent resonance frequency and frequency noise. Additionally, resonators are studied covered with SiOx dielectric layers of various thicknesses. The resonance frequency develops a nonmonotonic temperature dependence with increasing SiOx layer thickness. The increase in the noise is...

journal article 2008

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Direct demonstration of circulating currents in a controllable µ-SQUID generated by a 0 to µ transition of the weak links

Baselmans, J.J.A. (author), Wees, B.J. (author), Klapwijk, T.M. (author)

journal article 2002

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Fluctuations in the electron system of a superconductor exposed to a photon flux

De Visser, P.J. (author), Baselmans, J.J.A. (author), Bueno, J. (author), Llombart, N. (author), Klapwijk, T.M. (author)

In a superconductor, in which electrons are paired, the density of unpaired electrons should become zero when approaching zero temperature. Therefore, radiation detectors based on breaking of pairs promise supreme sensitivity, which we demonstrate using an aluminium superconducting microwave resonator. Here we show that the resonator also...

journal article 2014

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Enhancement of quasiparticle recombination in Ta and Al superconductors by implantation of magnetic and nonmagnetic atoms

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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Direct detection effect in small volume hot electron bolometer mixers

Baselmans, J.J.A. (author), Baryshev, A. (author), Reker, S.F. (author), Hajenius, M. (author), Gao, J.R. (author), Klapwijk, T.M. (author), Vachtomin, Y. (author), Maslennikov, S. (author), Antipov, S. (author), Voronov, B. (author), Gol'tsman, G. (author)

We measure 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 1.6?THz. We find that the small signal sensitivity of the receiver is underestimated by 35% due to the direct detection effect and that the optimal operating point is shifted to higher bias voltages when...

journal article 2005

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Quasiparticle Relaxation in Optically Excited High-Q Superconducting Resonators

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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Generation-recombination noise: The fundamental sensitivity limit for kinetic inductance detectors

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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Design of an integrated filterbank for DESHIMA: On-chip submillimeter imaging spectrograph based on superconducting resonators

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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On-chip filter bank spectroscopy at 600–700?GHz using NbTiN superconducting resonators

Endo, A. (author), Sfiligoj, C. (author), Yates, S.J.C. (author), Baselmans, J.J.A. (author), Thoen, D.J. (author), Javadzadeh, S.M.H. (author), Van der Werf, P.P. (author), Baryshev, A.M. (author), Klapwijk, T.M. (author)

We experimentally demonstrate the principle of an on-chip submillimeter wave filter bank spectrometer, using superconducting microresonators as narrow band-separation filters. The filters are made of NbTiN/SiNx/NbTiN microstrip line resonators, which have a resonance frequency in the range of 614-685?GHz, two orders of magnitude higher in...

journal article 2013