Superconductivity and incommensurate spin fluctuations in a generalized t-J model for the cuprates
Centro Atómico Bariloche and Instituto Balseiro, Comisión Nacional de Energía Atómica - 8400 Bariloche, Argentina
2 Instituto de Física de Rosario, Boulevard 27 de Febrero 210 bis, 2000 Rosario, Argentina
Accepted: 10 March 1997
We consider the slave-fermion Schwinger-boson decomposition of an effective model obtained through a systematic low-energy reduction of the three-band Hubbard Hamiltonian. The model includes a three-site term similar to that obtained in the large-U limit of the Hubbard model but of opposite sign for realistic or large O-O hopping. For parameters close to the most realistic ones for the cuprates, the mean-field solution exhibits d+s superconductivity (predominantly ) with a dependence on doping x very similar to the experimentally observed. We also obtained incommensurate peaks at wave vectors in the spin structure factor, which also agree with experiment.
PACS: 74.20.-z – Theories and models of superconducting state / 75.10.Jm – Quantized spin models
© EDP Sciences, 1997