PARAMETERS OF THE EFFECTIVE SINGLET-TRIPLET MODEL FOR BAND STRUCTURE OF HIGH-T_c CUPRATES BY VARIOUS APPROACHES
Korshunov M.M., Gavrichkov V.A., Ovchinnikov S.G., Pchelkina Z.V., Nekrasov I.A., Korotin M.A., Anisimov V.I.

Поступила в редакцию: 2 Декабря 2003

PACS: 74.72.h, 74.20.z, 74.25.Jb, 31.15.Ar

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We consider the problem of determining the parameters for high-T_c superconducting copper oxides. Various approaches, the ab initio LDA and LDA + U calculations and the generalized tight-binding (GTB) method for strongly correlated electron systems, are used to calculate hopping and exchange parameters of the effective singlet-triplet model for the CuO₂ layer. The resulting parameters are in remarkably good agreement with each other and with parameters extracted from experiment. This set of parameters is proposed for proper quantitative description of physics of hole-doped high-T_c cuprates in the framework of effective models.