A Two-Band Hubbard Model for Clusters of Doped Copper Oxides and Other Metal Oxides: Populations of Holes and Spin Densities by the Full VB CI Method

Abstract

The two-band Hubbard model for clusters of doped transition metal oxides is solved by the valence-bond (VB) full CI technique. It is found that the holes are mainly introduced upon oxygen sites of doped copper oxides, whereas they are localized on metal sites in the case of the Mott-Hubbard insulators such as iron and manganese oxides. The full VB Cl calculations indicate the important roles of both spin-flip (bitriplet) and spin-unflip (charge-transfer) excitations, which are responsible for electronic fluctuations (correlations) within doped copper oxides. Implications of these results are discussed in relation to the high- T c superccnductivity.

References

Page 1

	Year	Citations
Effective Hamiltonian for the superconducting Cu oxides Fu‐Chun Zhang, T. M. Rice Physical review. B, Condensed matter Superconducting MaterialEngineeringBismuth-based SuperconductorsSuperconductivityQuantum Materials	1988	3.4K
Band gaps and electronic structure of transition-metal compounds J. Zaanen, G. A. Sawatzky, J. W. Allen Physical Review Letters Metal Chain CompoundTransition Metal ChalcogenidesEngineeringPhysicsTheoretical Phase Diagram	1985	3K
Charge transfer excitations and superconductivity in “ionic” metals C. M. Varma, S. Schmitt‐Rink, Elihu Abrahams Solid State Communications Superconducting MaterialCharge ExcitationsEngineeringHigh-tc SuperconductivityPhysics	1987	944
Magnitude and Origin of the Band Gap in NiO G. A. Sawatzky, J. W. Allen Physical Review Letters Ii-vi SemiconductorTransition Metal ChalcogenidesEngineeringPhysicsBand-theory Predictions	1984	923
L2,3 xanes of the high Tc superconductor YBa2Cu3O≈7 with variable oxygen content A. Bianconi, A. Congiu Castellano, Marianna De Santis, Solid State Communications Superconducting MaterialHigh-tc SuperconductivityEngineeringPhysicsHigh-temperature Superconductivity	1987	208
Electronic structure of superconducting Cu oxides A. Fujimori, E. Takayama‐Muromachi, Y. Uchida Solid State Communications Materials ScienceSuperconducting MaterialHigh-tc SuperconductivityEngineeringApplied Physics	1987	141
Holes in Two-Dimensional CuO<sub>2</sub>System –Pairing Mechanism Emerging from Small-Cluster Studies– Masao Ogata, Hiroyuki Shiba Journal of the Physical Society of Japan Superconducting MaterialEngineeringMagnetic ResonanceChemistryMagnetism	1988	118
On the Mechanism of High-<i>T</i><sub>c</sub>Superconductivity Masatoshi Imada Journal of the Physical Society of Japan Copper HolesSuperconducting MaterialEngineeringChemistryNanoelectronics	1987	60
Extended Hubbard Models for Transition Metal Oxides and Halides: Importance of Spin and Charge Fluctuations in Charge Transfer Metals Kizashi Yamaguchi, Masayoshi Nakano, Hideo Namimoto, Japanese Journal of Applied Physics Hubbard ModelsSuperconducting MaterialEngineeringCharge TransportElectronic Structure	1988	41
Ab initio MO Studies on the Correlation and Spin Correlation Effects for Copper-Oxygen and Copper-Halogen Bonds in High-T<sub>c</sub> Copper Oxide Superconductors Kizashi Yamaguchi, Yoichi Takahara, Takayuki Fueno, Japanese Journal of Applied Physics Superconducting MaterialSpin Correlation EffectsEngineeringChemistryMolecular Design	1987	32

Page 1