Fluctuations beyond the Gutzwiller approximation in the slave-boson approach

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

DOI:https://doi.org/10.1103/PhysRevB.44.2403· OSTI ID:5440728

Jolicoeur, T ^[1]; Le Guillou, J C ^[2]

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1. Service de Physique Theorique, Centre d'Etudes Nucleaires de Saclay, F-91191 Gif-sur-Yvette CEDEX (France)
2. Laboratoire de Physique Theorique et Hautes Energies, Universite Paris VI, Tour 16, 1er etage, 4 place Jussieu, F-75252 Paris CEDEX 05 (France)

We study the Hubbard model through a functional-integral formulation proposed by Kotliar and Ruckenstein. A careful use of the U(1){sup {direct product}3} gauge symmetry of the bosonized action allows us to compute the complete one-loop correction to the free energy in the case of half-filled band. We extract the effective mass of the fermion in the metallic phase and show that the noninteracting limit is not recovered for vanishing on-site repulsion. The bosonic Hamiltonian must be adjusted order by order in perturbation theory.

• OSTI ID: 5440728
• Journal Information: Physical Review, B: Condensed Matter; (United States), Journal Name: Physical Review, B: Condensed Matter; (United States) Vol. 44:5; ISSN 0163-1829; ISSN PRBMD
• Country of Publication: United States
• Language: English

Related Subjects

656100* -- Condensed Matter Physics-- Superconductivity
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
BAND THEORY
FERMIONS
FLUCTUATIONS
FUNCTIONAL MODELS
GAUGE INVARIANCE
HAMILTONIANS
HIGH-TC SUPERCONDUCTORS
INVARIANCE PRINCIPLES
KONDO EFFECT
MATHEMATICAL OPERATORS
PERTURBATION THEORY
QUANTUM OPERATORS
SUPERCONDUCTORS
VARIATIONS