Antiferromagnetic and superconductive states in the three-band two-dimensional repulsive Hubbard model

The two-dimensional three-band Hubbard model is investigated using the temperature Green's function's formalism. Argument are presented in the favour of the weak-coupling approach, if the dimensionless coupling constant $U/t$ does not exceed 10-11. The normal state, the antiferromagnetic state with Neel ordering in the “copper” sublattice, and also the superconductive state with nontrivial Cooper pairing in channels with odd angular momenta are investigated. The possibility for other magnetic states in the model is discussed. Bibliography: 20 titles.