Single vortex motion and elementary pinning force in SNIS Josephson junctions

Thesis/Dissertation · Tue Jan 01 04:00:00 EST 1991

OSTI ID:5551022

Li, Qiang

A new family of superconductor-normal metal-insulator-superconductor (SNIS) Josephson junctions has been developed to study the motion of a single Abrikosov vortex under the influence of a Lorentz force from an applied transport current. The location of the vortex within the junction is determined by the diffraction pattern. Methods have been developed to nucleate a single vortex by applying a transport current in one strip of the junction and systematically to push the vortex to nearly any desired location within the junction by applying currents in either of the cross-strip legs of the junction. The vortex in thin film Pb was found to move stepwise from one pinning center to another. The average distance separating pinning centers in thin film Pb is about 1.0 {mu}m. The elementary pinning force f{sub {rho}} for a vortex in a pure Pb film was measured to be on the order of 10{sup {minus}13} N at reduced temperature t = T/{Tc} = 0.9, which is about one order of magnitude smaller than that for a Pb-BI film at this reduced temperature. The temperature dependence of f{sub {rho}} was found to be f{sub {rho}} {approximately} (1-T/{Tc}) above 6.5 K and f{sub {rho}} 6.5 K and f{sub {rho}} {approximately} (1T/{Tc}){sup 2/3} below 6.5 K. The feasibility of using the motion of a single cortex to store information and perform logic has been investigated. Since the Josephson voltage is in the range of tens of millivolts, the read and write operations can be done with rather simple electronics.

• Research Organization: Iowa State Univ. of Science and Technology, Ames, IA (United States)
• OSTI ID: 5551022
• Country of Publication: United States
• Language: English

Related Subjects

665412* -- Superconducting Devices-- (1992-)
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
BISMUTH
DISTANCE
ELECTRONIC EQUIPMENT
ELEMENTS
EQUIPMENT
FEASIBILITY STUDIES
FILMS
JOSEPHSON JUNCTIONS
JUNCTIONS
LEAD
LORENTZ FORCE
MAGNETIC FLUX
METALS
SUPERCONDUCTING JUNCTIONS
TEMPERATURE DEPENDENCE
THIN FILMS
USES