Exact results in a slave boson saddle point approach for a strongly correlated electron model

Journal Article · Fri Aug 15 04:00:00 EDT 2008 · Physical Review. B, Condensed Matter and Materials Physics

DOI:https://doi.org/10.1103/PHYSREVB.78.073108· OSTI ID:21143625

Fresard, Raymond ^[1]; Kopp, Thilo ^[2]

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1. Laboratoire CRISMAT, UMR CNRS-ENSICAEN 6508 and IRMA, FR3095 Caen (France)
2. Center for Electronic Correlations and Magnetism, Institute of Physics, Universitaet Augsburg, D-86135 Augsburg (Germany)

We revisit the Kotliar-Ruckenstein (KR) slave boson saddle point evaluation for a two-site correlated electron model. As the model can be solved analytically, it is possible to compare the KR saddle point results with the exact many-particle levels. The considered two-site cluster mimics an infinite-U single-impurity Anderson model with a nearest-neighbor Coulomb interaction: one site is strongly correlated with an infinite local Coulomb repulsion, which hybridizes with the second site, on which the local Coulomb repulsion vanishes. Making use of the flexibility of the representation, we introduce appropriate weight factors in the KR saddle point scheme. Ground-state and all excitation levels agree with the exact diagonalization results. Thermodynamics and correlation functions may be recovered in a suitably renormalized saddle point evaluation.

• OSTI ID: 21143625
• Journal Information: Physical Review. B, Condensed Matter and Materials Physics, Journal Name: Physical Review. B, Condensed Matter and Materials Physics Journal Issue: 7 Vol. 78; ISSN 1098-0121
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
BOSONS
COMPARATIVE EVALUATIONS
CORRELATION FUNCTIONS
COULOMB FIELD
ELECTRON CORRELATION
EXCITATION
FLEXIBILITY
GROUND STATES
IMPURITIES
INTERACTIONS
PARTICLES
RENORMALIZATION
SIMULATION
THERMODYNAMICS