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Title: Mechanism of hole attraction in the extended Hubbard model

Journal Article · · Physical Review, B: Condensed Matter; (United States)
 [1]
  1. Institute of Physics, Estonian Academy of Sciences Riia 142, EE2400 Tartu (Estonia)

The expansion in the Cu-O hybridization energy, [ital t], usually used for the simplification of the extended Hubbard Hamiltonian, is shown to meet with difficulties for the known parameters of CuO[sub 2] planes of cuprate perovskites. An expansion in a power series in [lambda][ital t], [lambda][approx]0.1, is suggested, which is applicable for these values of parameters and in which the Hubbard repulsion and the Cu-O hybridization are considered on an equal footing. A Hamiltonian obtained with the help of the expansion for the lower part of the energy spectrum, is equivalent to the [ital t]-[ital J] Hamiltonian and the corresponding states are some generalizations of the Zhang-Rice singlets. The Hamiltonian contains terms describing a static attraction between holes and for reasonable sets of parameters the attraction is approximately equal to a half of the superexchange constant.

OSTI ID:
6608840
Journal Information:
Physical Review, B: Condensed Matter; (United States), Vol. 47:17; ISSN 0163-1829
Country of Publication:
United States
Language:
English