Spin and charge fluctuation in an extended Hubbard model of oxide superconductors

Journal Article · Mon Nov 01 04:00:00 EST 1993 · Physical Review, B: Condensed Matter; (United States)

DOI:https://doi.org/10.1103/PhysRevB.48.13949· OSTI ID:5990650

Bhattacharya, A; Wang, C S ^[1]

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1. Department of Physics and Center for Superconductivity Research, University of Maryland, College Park, Maryland 20742 (United States)

Antiferromagnetic spin fluctuations and charge-transfer correlation are studied in an extended Hubbard model of cuprate superconductors. We have carried out finite-temperature Monte Carlo and variational Monte Carlo simulations of CuO[sub 2] lattices described by a three-band Hubbard model. Using parameters derived by local-density-functional theory, our results appear to be consistent with experimental data. At half-filling, we find strong antiferromagnetic correlation with large local moment on copper sites and evidence of a charge-transfer gap. Upon doping, the antiferromagnetic correlations decrease; the excess holes primarily go onto the oxygen sites, while additional electrons prefer the copper sites. Equal-time pairing correlation functions suggest that extended [ital s]-wave and [ital d]-wave pairing are possible in this model.

• OSTI ID: 5990650
• Journal Information: Physical Review, B: Condensed Matter; (United States), Journal Name: Physical Review, B: Condensed Matter; (United States) Vol. 48:18; ISSN PRBMDO; ISSN 0163-1829
• Country of Publication: United States
• Language: English

Related Subjects

665411* -- Basic Superconductivity Studies-- (1992-)
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ANTIFERROMAGNETISM
CALCULATION METHODS
CHARGE EXCHANGE
COMPUTERIZED SIMULATION
COPPER COMPOUNDS
CRYSTAL MODELS
CUPRATES
FLUCTUATIONS
HIGH-TC SUPERCONDUCTORS
HUBBARD MODEL
MAGNETISM
MATHEMATICAL MODELS
MONTE CARLO METHOD
OXYGEN COMPOUNDS
SIMULATION
SUPERCONDUCTORS
TRANSITION ELEMENT COMPOUNDS
VARIATIONAL METHODS
VARIATIONS