Mean-field results of the multiple-band extended Hubbard model for the square-planar CuO[sub 2] lattice

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

DOI:https://doi.org/10.1103/PhysRevB.48.7355· OSTI ID:6022864

Nimkar, S ^[1]; Sarma, D D ^[2]; Krishnamurthy, H R ^[3]; Ramasesha, S ^[2]

---

1. Solid State and Structural Chemistry Unit and Department of Physics, Indian Institute of Science, Bangalore 560 012 (India)
2. Solid State and Structural Chemistry Unit and Jawaharlal Nehru Center for Advanced Scientific Research, Indian Institute of Science, Bangalore 560 012 (India)
3. Department of Physics and Jawaharlal Nehru Center for Advanced Scientific Research, Indian Institute of Science, Bangalore 560 012 (India)

We obtain metal-insulator phase diagrams at half-filling for the five-band extended Hubbard model of the square-planar CuO[sub 2] lattice treated within a Hartree-Fock mean-field approximation, allowing for spiral spin-density waves. We indicate the existence of an insulating phase (covalent insulator) characterized by strong covalency effects, not identified in the earlier Zaanen-Sawatzky-Allen phase diagram. While the insulating phase is always antiferromagnetic, we also obtain an antiferromagnetic metallic phase for a certain range of interaction parameters. Performing a nonperturbative calculation of [ital J][sub eff], the in-plane antiferromagnetic interaction is presented as a function of the parameters in the model. We also calculate the band gap and magnetic moments at various sites and discuss critically the contrasting interpretation of the electronic structure of high-[ital T][sub [ital c]] materials arising from photoemission and neutron-scattering experiments.

• OSTI ID: 6022864
• Journal Information: Physical Review, B: Condensed Matter; (United States), Vol. 48:10; ISSN 0163-1829
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
HIGH-TC SUPERCONDUCTORS
HUBBARD MODEL
COPPER OXIDES
ELECTRONIC STRUCTURE
HARTREE-FOCK METHOD
MEAN-FIELD THEORY
PHASE DIAGRAMS
TWO-DIMENSIONAL CALCULATIONS
CALCULATION METHODS
CHALCOGENIDES
COPPER COMPOUNDS
CRYSTAL MODELS
DIAGRAMS
MATHEMATICAL MODELS
OXIDES
OXYGEN COMPOUNDS
SUPERCONDUCTORS
TRANSITION ELEMENT COMPOUNDS
665411* - Basic Superconductivity Studies- (1992-)