Pairing, condensation, and superconductivity described by a Hubbard model with an attractive interaction

Journal Article · Sun Sep 01 04:00:00 EDT 1991 · Physical Review, B: Condensed Matter; (United States)

DOI:https://doi.org/10.1103/PhysRevB.44.5190· OSTI ID:5293401

Gyorffy, B L ^[1]; Staunton, J B ^[2]; Stocks, G M ^[3]

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1. H. H. Wills Physics Laboratory, Tyndall Avenue, Bristol BS8 1, TL (United Kingdom)
2. Department of Physics, University of Warwick, Coventry (United Kingdom)
3. Oak Ridge National Laboratory, Oak Ridge, Tennessee (USA)

We have developed a method for studying superconductivity in the negative-{ital U} Hubbard model. It is based on the Hubbard-alloy-analogy approximation applied to the Gor'kov equation for the model. We find that, unlike the case of the BCS solution, the formation of pairs and their condensation into a superconducting ground state take place at two different temperatures. We calculate the condensation temperature {ital T}{sub {ital c}} for all {ital U} and discuss the nature of the normal state which, for large enough {ital U}, features a macroscopically large number of pairs. Briefly, we argue that the model has relevance for high-temperature superconductors.

• DOE Contract Number: AC05-84OR21400
• OSTI ID: 5293401
• Journal Information: Physical Review, B: Condensed Matter; (United States), Journal Name: Physical Review, B: Condensed Matter; (United States) Vol. 44:10; ISSN PRBMD; ISSN 0163-1829
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360204* -- Ceramics
Cermets
& Refractories-- Physical Properties
656100 -- Condensed Matter Physics-- Superconductivity
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
GORKOV-ELIASHBERG THEORY
HIGH-TC SUPERCONDUCTORS
PHYSICAL PROPERTIES
SUPERCONDUCTORS
THERMODYNAMIC PROPERTIES
TRANSITION TEMPERATURE