Spatial structure of superconducting correlations of d_(x2- y2) symmetry in high-temperature superconductors

摘要

The spatial structure of the correlation function of the order parameter of the d_(x2 - y2) symmetry has been investigated within the t-J model in the generalized mean field approximation taking into account the "no-double occupancy" constraint due to strong electron correlations. A slow decay of the correlation function to the thirtieth coordination sphere has been found. The limitation by pairing of only the nearest neighbors makes it possible to take into account less than 17% of the superconducting correlations.