Barends, R., Van Vliet, S., Baselmans, J. J. A., Yates, S. J. C., Gao, J. R., Klapwijk, T. M.
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...
Contribution of dielectrics to frequency and noise of NbTiN superconducting resonators (2008)
Barends, R., Hortensius, H. L., Zijlstra, T., Baselmans, J. J. A., Yates, S. J. C., Gao, J. R., ...
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...
Quasiparticle relaxation in optically excited high-Q superconducting resonators (2008)
Barends, R., Baselmans, J. J. A., Yates, S. J. C., Gao, J. R., Hovenier, J. N., Klapwijk, T. M.
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 aluminium,...
IF impedance and mixer gain of NbN hot electron bolometers (2007)
Kooi, J. W., Baselmans, J. J. A., Hajenius, M., Gao, J. R., Klapwijk, T. M., Dieleman, P., ...
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...
Crystallization of Nd2Fe17Bx from its stoichiometric melt composition (2007)
Gao, J. R., Volkmann, T., Yang, S., Reutzel, S., Herlach, D. M., Song, X. P.
Containerless solidification of gas-atomized Nd10Fe85B5 melt droplets was carried out using the drop tube technique. The phase constituents and microstructure of the solidified samples were...
Hajenius, M., Baselmans, J. J. A., Baryshev, A., Gao, J. R., Klapwijk, T. M., Kooi, J. W., ...
We present a complete experimental characterization of a quasioptical twin-slot antenna coupled small area (1.0×0.15 µm^2) NbN hot electron bolometer (HEB) mixer compatible with currently available...
Stability of heterodyne terahertz receivers (2006)
Kooi, J. W., Baselmans, J. J. A., Baryshev, A., Schieder, R., Hajenius, M., Gao, J. R., ...
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...
Antenna model for wire lasers (2006)
Orlova, E.E., Hovenier, J.N., Klaassen, T.O., Kasalynas, I, Adam, A.J.L., Gao, J.R., ...
Solidification of Co-Cu alloys in the metastable miscibility gap under low gravity conditions (2006)
Kolbe, M., Gao, J.R., Reutzel, S.
Liquid Cu-Co shows a metastable miscibility gap where the homogeneous melt separates into the Co-rich L1-liquid and the Cu-rich L2-liquid. The required undercooling of the melt of > 120 K can be...
Reduced noise in NbN hot-electron bolometer mixers by annealing (2006)
Yang, Z.Q., Hajenius, M., Baselmans, J.J.A., Gao, J.R., Voronov, B., Gol'tsman, G.N.
Gao, J.R., Hovenier, J.W., Yang, Z.Q., Baselmans, J.J.A., Baryshev, A., Hajenius, M., ...
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...
Low noise NbN superconducting hot electron bolometer mixers at 1.9 and 2.5 THz (2004)
Hajenius, M., Baselmans, J.J.A., Gao, J.R., Klapwijk, T.M., Voronov, B., ...
Optical squeezing in temporal, polarization, and spatial domains (2003)
Symul, T., Bowen, W. P., Schnabel, R., Treps, N., Buchler, B. C., Ralph, T. C., ...
We present methods of transforming the standard quadrature amplitude squeezing of a continuous-wave light beam to its Stokes parameters and transverse spatial modes statistics. These two states of...
Superconducting transition metal nitride films for THz SIS mixers (2001)
Iosad, N.N., Roddatis, V.V., Polyakov, S.N., Varlashkin, A.V., Jackson, B.D., Dmitriev, P.N., ...
Gao, J.R., Kerkhof, J.J.B., Verwerft, M., Magnée, P., Wees, B.J. Van, Klapwijk, T.M., ...
Tin-based superconducting contacts have been successfully made to GaAs/AlGaAs heterostructures in several groups. To identify whether the superconductor contacts directly with the two-dimensional...
Gao, J.R., Kerkhof, J.J.B., Verwerft, M., Magnée, P., Wees, B.J. Van, Klapwijk, T.M., ...
Tin-based superconducting contacts have been successfully made to GaAs/AlGaAs heterostructures in several groups. To identify whether the superconductor contacts directly with the two-dimensional...
Gao, J.R., Kerkhof, J.J.B., Verwerft, M., Magnée, P., Wees, B.J. Van, Klapwijk, T.M., ...
Tin-based superconducting contacts have been successfully made to GaAs/AlGaAs heterostructures in several groups. To identify whether the superconductor contacts directly with the two-dimensional...
Gao, J.R., Wees, B.J. Van, Kuipers, J.J., Heida, J.P., Klapwijk, T.M.
Split gate quantum point contacts on a two-dimensional electron gas (2DEG) of GaAs/AlGaAs heterostructures are fabricated using conventional optical lithography. The typical opening of the split...
Gao, J.R., Heida, J.P., Wees, B.J. Van, Klapwijk, T.M., Borghs, G., Foxon, C.T.
We fabricated superconducting Sn/Pd contacts to a two-dimensional electron gas (2DEG) in GaAs/AlGaAa heterostructurcs by an alloying technique. A dip around zero bias and peaks at finite voltages...
Gao, J.R., Wees, B.J. Van, Kuipers, J.J., Heida, J.P., Klapwijk, T.M.
Split gate quantum point contacts on a two-dimensional electron gas (2DEG) of GaAs/AlGaAs heterostructures are fabricated using conventional optical lithography. The typical opening of the split...
Gao, J.R., Heida, J.P., Wees, B.J. Van, Klapwijk, T.M., Borghs, G., Foxon, C.T.
We fabricated superconducting Sn/Pd contacts to a two-dimensional electron gas (2DEG) in GaAs/AlGaAa heterostructurcs by an alloying technique. A dip around zero bias and peaks at finite voltages...
Low temperature current transport of Sn-GaAs contacts (1993)
Gao, J.R., Heida, J.P., Wees, B.J. Van, Bakker, S., Klapwijk, T.M., Alphenaar, B.W.
We measure low temperature current transport properties of superconducting Sn contacts to p+-GaAs. For contacts alloyed at 450 °C, the current-voltage characteristics show a strong dependence on...
Low temperature current transport of Sn-GaAs contacts (1993)
Gao, J.R., Heida, J.P., Wees, B.J. Van, Bakker, S., Klapwijk, T.M., Alphenaar, B.W.
We measure low temperature current transport properties of superconducting Sn contacts to p+-GaAs. For contacts alloyed at 450 °C, the current-voltage characteristics show a strong dependence on...