Current-carrying states in superconducting multilayers with Josephson interlayer coupling for temperatures close to T{sub c0}: A microscopic theory

Journal Article · Fri Aug 01 04:00:00 EDT 1997 · Physical Review, B: Condensed Matter

DOI:https://doi.org/10.1103/PhysRevB.56.2764· OSTI ID:528083

Kuplevakhsky, S V ^[1]; Naydenov, S V ^[2]

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1. Department of Physics, Kharkov State University, 310077 Kharkov (Ukraine)
2. Institute for Single Crystals, 310164 Kharkov (Ukraine)

We present a complete, self-consistent, microscopic description of current-carrying states in all sorts of superconducting multilayers with interlayer Josephson coupling near the bulk critical temperature, T{sub c0}: superconductor-insulator (SI) superlattices with or without intrabarrier exchange interactions and nonmagnetic impurities inside superconducting (S) layers, pure structures with point-contact-type interlayer coupling, superconductor{endash}normal-metal (SN) superlattices with an arbitrary concentration of nonmagnetic impurities, and SN superlattices in the dirty limit with paramagnetic impurities inside N barriers. We have obtained closed analytical expressions for the Josephson current as a function of an S layer thickness, a. For all these systems drastic deviations from a single-junction case were found: a reduction of the critical Josephson current j{sub c} for pure SI superlattices with a{le}{xi}{sub 0}, nontrivial current-phase dependence for multilayers with point-contact-type coupling and a{le}{xi}{sub 0}, and nontrivial temperature dependence of j{sub c} for SN superlattices. Mathematically, our approach is based solely on the use of a microscopic free-energy functional. For a{gt}{xi}{sub 0}, we reduce this functional to a Ginzburg-Landau-type functional with an extra term accounting for the interface free energy. For SI superlattices, in an appropriate limit this latter reduces to a Lawrence-Doniach-type functional with microscopically defined coefficients. {copyright} {ital 1997} {ital The American Physical Society}

• OSTI ID: 528083
• Journal Information: Physical Review, B: Condensed Matter, Journal Name: Physical Review, B: Condensed Matter Journal Issue: 5 Vol. 56; ISSN 0163-1829; ISSN PRBMDO
• Country of Publication: United States
• Language: English

Related Subjects

66 PHYSICS
COUPLING
CRITICAL CURRENT
CRITICAL TEMPERATURE
ELECTRIC CONTACTS
FREE ENERGY
GINZBURG-LANDAU THEORY
HIGH-TC SUPERCONDUCTORS
IMPURITIES
JOSEPHSON EFFECT
JOSEPHSON JUNCTIONS
SUPERCONDUCTING FILMS
SUPERLATTICES
TRANSITION TEMPERATURE