|   | 
Details
   web
Records
Author Floet D. W.; Gao J. R.; Klapwijk T. M.; de Korte P. A. J.
Title (up) Bias Dependence of the Thermal Time Constant in Nb Superconducting Diffusion-Cooled HEB Mixers Type Journal Article
Year 2000 Publication Appl. Phys. Lett. Abbreviated Journal Appl. Phys. Lett.
Volume 77 Issue Pages 1719
Keywords
Abstract We present an experimental study of the intermediate frequency bandwidth of a Nb diffusion-cooled hot-electron bolometer mixer for different bias voltages. The measurements show that the bandwidth increases with increasing voltage. Analysis of the data reveals that this effect is mainly caused by a decrease of the intrinsic thermal time of the mixer and that the effect of electrothermal feedback through the intermediate frequency circuit is small. The results are understood using a qualitative model, which takes into account the different effective diffusion constants in the normal and superconducting domains.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number RPLAB @ atomics90 @ Serial 971
Permanent link to this record
 

 
Author Kerman, A. J.; Dauler, E. A.; Yang, J. K. W.; Rosfjord, K. M.; Anant, V.; Berggren, K. K.; Gol’tsman, G. N.; Voronov, B. M.
Title (up) Constriction-limited detection efficiency of superconducting nanowire single-photon detectors Type Journal Article
Year 2007 Publication Appl. Phys. Lett. Abbreviated Journal Appl. Phys. Lett.
Volume 90 Issue 10 Pages 101110 (1 to 3)
Keywords SSPD, SNSPD
Abstract We investigate the source of the large variations in the observed detection efficiencies of superconducting nanowire single-photon detectors between many nominally identical devices. Through both electrical and optical measurements, we infer that these variations arise from “constrictions:” highly localized regions of the nanowires where the effective cross-sectional area for superconducting current is reduced. These constrictions limit the bias-current density to well below its critical value over the remainder of the wire, and thus prevent the detection efficiency from reaching the high values that occur in these devices when they are biased near the critical current density.

This work is sponsored by the United States Air Force under Contract No. FA8721-05-C-0002.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0003-6951 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number Serial 1433
Permanent link to this record
 

 
Author Gousev, Yu. P.; Semenov, A. D.; Pechen, E. V.; Varlashkin, A. V.; Nebosis, R. S.; Renk K. F
Title (up) Coupling of terahertz radiation to a high-Т(с) superconducting hot electron bolometer mixer Type Journal Article
Year 1996 Publication Abbreviated Journal Appl. Phys. Lett.,
Volume 69 Issue Pages 691-693
Keywords
Abstract We report on efficient coupling of THz radiation to a high-T(c) superconducting hot electron bolometer that is suitable for heterodyne detection. Our quasioptical system consisted of a planar self-complementary spiral antenna on a dielectric substrate clamped to an extended hyperhemispherical lens. The antenna was integrated into a co-planar line for broadband intermediate frequency matching. Measurements in the homodyne regime at a frequency of 2.5 THz showed a radiation pattern with a beam width of 1° and a coupling efficiency of 0.1. We measured, at an intermediate frequency of 1.5 GHz, an output noise temperature of'160 K and estimated for the device, operated in the heterodyne regime, a system noise temperature of 30 000 K. We also discuss possibilities of significant improvement of the sensitivity.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number RPLAB @ atomics90 @ Serial 958
Permanent link to this record
 

 
Author Mannino, Giovanni; Spinella, Corrado; Ruggeri, Rosa; La Magna, Antonino; Fisicaro, Giuseppe; Fazio, Enza; Neri, Fortunato; Privitera, Vittorio
Title (up) Crystallization of implanted amorphous silicon during millisecond annealing by infrared laser irradiation Type Journal Article
Year 2010 Publication Applied Physics Letters Abbreviated Journal Appl. Phys. Lett.
Volume 97 Issue 2 Pages 3
Keywords Annealing
Abstract We investigated the homogenous nucleation of crystalline grains in amorphous Si during transient temperature pulse of few milliseconds IR laser irradiation. The crystallized volume fraction is ~80%. Significant crystallization occurs in nonsteady regime because of the rapid temperature variation (106 °C/s). Our model combines the time evolution of the crystal grain population with the consumption of the amorphous volume due to the growth of grains. Thanks to the experimental approach based on a laser source to heat α-Si and the theoretical model we extended the description of the spontaneous crystallization up to 1323 K or 250 K above the temperature investigated by conventional annealing.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN ISBN Medium
Area Expedition Conference
Notes Annealing Approved no
Call Number RPLAB @ gujma @ Serial 691
Permanent link to this record
 

 
Author Swetz, D. S.; Bennett, D. A.; Irwin, K. D.; Schmidt, D. R.; Ullom, J. N.
Title (up) Current distribution and transition width in superconducting transition-edge sensors Type Journal Article
Year 2012 Publication Appl. Phys. Lett. Abbreviated Journal Appl. Phys. Lett.
Volume 101 Issue Pages 242603
Keywords
Abstract Present models of the superconducting-to-normal transition in transition-edge sensors (TESs) do not describe the current distribution within a biased TES. This distribution is complicated by normal-metal features that are integral to TES design. We present a model with one free parameter that describes the evolution of the current distribution with bias. To probe the current distribution experimentally, we fabricated TES devices with different current return geometries. Devices where the current return geometry mirrors current flow within the device have sharper transitions, thus allowing for a direct test of the current-flow model.Measurements from these devices show that current meanders through a TES low in the resistivetransition but flows across the normal-metal features by 40% of the normal-state resistance. Comparison of transition sharpness between device designs reveals that self-induced magnetic fields play an important role in determining the width of the superconducting transition.
Address TES, current distribution
Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN ISBN Medium
Area Expedition Conference
Notes Recommended by Klapwijk Approved no
Call Number Serial 930
Permanent link to this record