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Applied Superconductivity, IEEE Transactions on

Issue 2 • Date June 1991

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Displaying Results 1 - 5 of 5
  • Quantum flux parametron: a single quantum flux device for Josephson supercomputer

    Publication Year: 1991 , Page(s): 77 - 89
    Cited by:  Papers (20)  |  Patents (2)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1357 KB)  

    A quantum flux parametron (QFP), a single quantum flux superconductive device that has a potential of up to 100-GHz switching with nW-order power dissipation, is considered. The potential of the QFP and key technologies when QFPs are applied to a Josephson supercomputer are described. Switching speed, stability, and power dissipation of a QFP are discussed. QFP gates, circuits, and systems are next described. Then, ultra-fast clock distribution using a standing wave is explained. High-speed operation at more than 10 GHz and 10/sup 14/ error-free operations per QFP have been demonstrated. Finally described is a high-density packaging scheme by three-dimensional integration, which is very important for ultra-high speed circuits because the propagation delay becomes dominant in such circuits.<> View full abstract»

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  • Quantum flux parametron with magnetic flux regulator

    Publication Year: 1991 , Page(s): 90 - 94
    Cited by:  Papers (2)  |  Patents (2)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (430 KB)  

    A magnetic flux regulator for a quantum flux parametron (QFP) is proposed. The regulator is formed with a parallel connection of a Josephson junction across activation inductors building an RF-SQUID (superconducting quantum interference device). This junction makes a nonlinear bypass channel for magnetic activation flux and contributes to regulation of applied flux and elimination of undesirable external noises. Using this flux regulator, the activation condition tolerance is not only improved, but also a higher speed transition from a nonactivated state to an activated state is expected. QFP operations with the regulators have been observed with integrated circuits.<> View full abstract»

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  • A model and equivalent circuit for a superconducting flux flow transistor

    Publication Year: 1991 , Page(s): 95 - 101
    Cited by:  Papers (19)  |  Patents (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (614 KB)  

    A three-terminal high-frequency active device made of a single film of a high T/sub c/ superconductor that is based on the magnetic control of flux flow is presented. The device is composed of parallel weak links with a nearby magnetic control line. A model has been developed that is based on solving the equation of motion of Abrikosov vortices subject to Lorentz viscous and pinning forces, as well as magnetic surface barriers. The model has been used to predict device transit time (computed from flux velocity) and device I-V curves. The predictions are compared to measured parameters with resulting very good agreement.<> View full abstract»

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  • Possible three-terminal device with YBCO angle grain boundary

    Publication Year: 1991 , Page(s): 102 - 107
    Cited by:  Papers (2)  |  Patents (3)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (579 KB)  

    The DC and AC Josephson effects were observed in YBa/sub 2/Cu/sub 3/O/sub 7-a/ (YBCO) bridges with metal-organic chemical vapor deposited (MOCVD) thin films on View full abstract»

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  • Current distribution, resistance, and inductance for superconducting strip transmission lines

    Publication Year: 1991 , Page(s): 108 - 115
    Cited by:  Papers (65)  |  Patents (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (683 KB)  

    A method for the calculation of the current distribution, resistance, and inductance matrices for a system of coupled superconducting transmission lines having finite rectangular cross-section is presented. These calculations allow accurate characterization of both high-T/sub c/ and low-T/sub c/ superconducting strip transmission lines. For a single stripline geometry with finite ground planes, the current distribution, resistance, inductance, and kinetic inductance are calculated as functions of the penetration depth for various film thicknesses. These calculations are then used to determine the penetration depth for Nb, NbN, and YBa/sub 2/Cu/sub 3/O/sub 7-x/ superconducting thin films from the measured temperature dependence of the resonant frequency of a stripline resonator. The calculations are also used to convert measured temperature dependence of the quality factor to the intrinsic surface resistance as a function of temperature for an Nb stripline resonator.<> View full abstract»

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IEEE Transactions on Applied Superconductivity contains articles on the applications of superconductivity and other relevant technology.

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Editor-in-Chief
Britton L. T. Plourde
Syracuse University
bplourde@syr.edu
http://www.phy.syr.edu/~bplourde