Condensed Matter Physics, 1996, No. 7, p. 139-148, English
A quasiparticle spectrum of doped holes and their superconducting pairing in the CuO2 plane is studied within a spin polaron t-J model on a two-sublattice antiferromagnet. A self-consistent system of equations for hole and magnon matrix Green functions in the noncrossing approximation is solved numerically by the fast Fourier transformation method. We obtain a strong renormalization of the hole spectrum due to spin fluctuations that result in formation of spin polarons described by the coherent part of the spectrum. We also observe a singlet d-wave superconducting pairing for two spin polarons on different sublattices, mediated by spin-fluctuation exchange. A maximal superconducting temperature Tc ~ 0.01t is obtained around the hole concentration 0.25 for t=0.4J. We argue that the superconducting pairing of spin polarons for the t-J model with strong electron correlations represents the mechanism of high-temperature superconductivity.Comments: Refs. 26, Figs. 5, Tabs. 0.
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