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Reduction of Trapped Magnetic Flux in a Superconducting Groundplane

IP.com Disclosure Number: IPCOM000053211D
Original Publication Date: 1981-Sep-01
Included in the Prior Art Database: 2005-Feb-12

Publishing Venue

IBM

Related People

Authors:
Gheewalla, TR Harris, EP Kirchner, CJ Tuckerman, DB [+details]

Abstract

In superconductive circuitry, and especially that using Josephson circuits, the presence of magnetic flux trapped in underlying groundplanes is a problem, since the trapped flux changes the switching characteristics of the devices. One technique to eliminate this trapped flux is to ensure that the groundplane enters the superconducting state in an ambient perpendicular magnetic field of magnitude less than Phi(O) /2A, where Phi(O) is a flux quantum and A is the groundplane area. However, for typical groundplane areas this condition implies a very low magnetic field level. In order to provide a continuous groundplane but which appears to be comprised of a plurality of segments of groundplane having small areas, a groundplane is provided having a spatially tailored T(c).