Theory of critical currents and perpendicular upper critical fields for superconducting proximity systems

Thesis/Dissertation · Mon Dec 31 23:00:00 EST 1984

OSTI ID:5813062

Biagi, K R

This thesis is divided into two sections, each dealing with the response of a superconducting proximity system to an applied magnetic field. In Section I, the maximum supercurrent that can be carried in an applied perpendicular magnetic field by a superconducting normal-metal superconducting (SNS) junction consisting of a square normal-metal layer sandwiched between two crossed perpendicular superconducting strips is investigated theoretically. For weak applied fields, the critical current is suppressed reversibly as induced Meissner screening currents flow into the SNS sandwich and generate a spatially varying magnetic field largely parallel to the junction, thereby altering the local phase difference. For stronger applied fields, the critical current is changed irreversibly as vortices enter and become pinned in the junction. In Section II, Eilenberger's quasi-classical formulation of superconductivity is used to derive an equation for the upper critical field of a multilayered SN system in a perpendicular magnetic field. The alternating layers are coupled via the proximity effect and are in the dirty limit.

• Research Organization: Iowa State Univ. of Science and Technology, Ames (USA)
• DOE Contract Number: W-7405-ENG-82
• OSTI ID: 5813062
• Country of Publication: United States
• Language: English

Related Subjects

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656101 -- Solid State Physics-- Superconductivity-- General Theory-- (-1987)
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
CRITICAL CURRENT
CRITICAL FIELD
CURRENTS
ELECTRIC CONDUCTIVITY
ELECTRIC CURRENTS
ELECTRICAL PROPERTIES
JUNCTIONS
MAGNETIC FIELDS
PHYSICAL PROPERTIES
PROXIMITY EFFECT
SUPERCONDUCTING JUNCTIONS
SUPERCONDUCTIVITY