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Title: Dependence of the polarizability of the Cu sub 4 O sub 8 cluster on the doping, the weight of the oxygen-hole state, and the excitation gaps in the three-band Hubbard model

Journal Article · · Physical Review, B: Condensed Matter; (United States)
;  [1]
  1. Solid State and Structural Chemistry Unit, Indian Institute of Science, Bangalore 560 012 (India)

We have obtained the model exact static polarizability of the Cu{sub 4}O{sub 8} cluster within the three-band Hubbard model for different doping levels. The excitation gaps as well as the weight of the O{sup {minus}} (oxygen-hole) state in the ground-state wave function have been exactly computed. The parameters of the model are varied to alter the excitation gaps as well as the weight of the O{sup {minus}} state in order to examine the dependence of the polarizability on these quantities. The Cu{sub 4}O{sub 8} cluster is highly polarizable, the polarizability increasing with the doping level. The polarizability is large when the excitation gap is charge-transfer-like and increases with the decreasing gap; it also increases markedly with the increase in the weight of the O{sup {minus}} state. Experimentally, the {ital T}{sub {ital c}} in the cuprates is highest for the range of the weight of O{sup {minus}} for which the lattice is highly polarizable.

OSTI ID:
5156131
Journal Information:
Physical Review, B: Condensed Matter; (United States), Vol. 44:13; ISSN 0163-1829
Country of Publication:
United States
Language:
English