BCS pairing in a correlated narrow-band metal

Journal Article · Wed Sep 01 04:00:00 EDT 1993 · Physical Review, B: Condensed Matter; (United States)

DOI:https://doi.org/10.1103/PhysRevB.48.6509· OSTI ID:5429769

Ramakumar, R; Kumar, R; Jain, K P ^[1]; Chancey, C C ^[2]

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1. Department of Physics, Indian Institute of Technology, New Delhi 110016 (India)
2. Department of Physics and Chemistry, Purdue University Calumet, Hammond, Indiana 46323-2094 (United States)

A theoretical study of BCS pairing in an extended Hubbard model with on-site repulsion ([ital U]) and a BCS pairing field ([ital V]) is presented. Treating the effect of [ital U] in the Gutzwiller approximation, we study the effect of increasing [ital U] in the Fermi-liquid phase, on the BCS pairing due to [ital V]. It is found that the superconducting energy gap ([Delta]) is strongly enhanced in the correlated metallic phase near half-filling of the band due to the localization effects of [ital U]. Further, the ground state is found to be superconducting even when [vert bar][ital V][vert bar][lt][ital U], contrary to the prediction in a Hartree-Fock treatment.

• OSTI ID: 5429769
• Journal Information: Physical Review, B: Condensed Matter; (United States), Journal Name: Physical Review, B: Condensed Matter; (United States) Vol. 48:9; ISSN 0163-1829; ISSN PRBMDO
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360207* -- Ceramics
Cermets
& Refractories-- Superconducting Properties-- (1992-)
BCS THEORY
COOPER PAIRS
CORRELATED-PARTICLE MODELS
CRYSTAL MODELS
EFFECTIVE MASS
ENERGY GAP
HIGH-TC SUPERCONDUCTORS
HUBBARD MODEL
MASS
MATHEMATICAL MODELS
PARTICLE MODELS
SUPERCONDUCTORS