Antiferromagnetic exchange and spin-fluctuation pairing in cuprates

Nikolay M. Plakida

Joint Institute for Nuclear Research, 141980 Dubna, Russia

Mechanisms of superconducting pairing mediated by antiferromagnetic (AFM) exchange and by spin-fluctuations are considered within the effective two-band Hubbard model for a copper-oxide plane. It is proved that retardation effects for AFM exchange pairing are unimportant that results in pairing of all the carries in the conduction band and high Tc proportional to the Fermi energy. The spin-fluctuations caused by the kinematic interaction gives additional contribution to the d-wave pairing. Tc dependence on the lattice constants (or pressure) and oxygen isotope shift are explained. Comparison with the results for the t-J model is given.