The Interplay of Phonon and Magnetic Mechanism of Pairing in Strongly Correlated Electron System of High- T_c Cuprates

摘要

We consider magnetic mechanism of superconducting pairing in the effective low energy t - t' - t" - J~* model with all parameters calculated ab initio. Interaction of strongly correlated electrons with different phonon modes is also incorporated. In a BCS type theory, the d_(x~2-y~2) gap is given by a sum of magnetic and phonon contributions. The main contribution to the only fitting parameter G is determined by a competition of the breathing and buckling modes. Fitting the parameter G from the isotope effect, we obtain that magnetic and phonon contributions to the critical temperature T_c work together and are of the same order of magnitude.