HOLE HOLE SUPERCONDUCTING PAIRING IN THE T-J MODEL INDUCED BY LONG-RANGE SPIN-WAVE EXCHANGE

Long-range (r approximately p(F)-1 much greater than lattice spacing) spin-wave exchange produces a very strong pairing of the holes. Soluti ons of the BCS-type equation for the superconducting pp DELTA are foun d for various symmetries. The strongest pairing corresponds to d wave symmetry. The physical reasons for the strong pairing are: (1) the typ ical spin-wave energy is higher than the Fermi energy, (2) a ''collaps e'' effect in the attractive potential (-1/r2) describing the interact ion between two holes and (3) the hole dispersion is strongly asymmetr ic. At hole concentrations delta approximately 0.01-0.3 we get DELTA a pproximately T(c) approximately epsilon(F). At very low concentration of the holes the many-body wave function of the ground state decays in to a product of two-hole bound states.