Isotope Effect in the Model of Strongly Correlated Electrons with the Magnetic and Phonon Superconducting Pairing Mechanisms

摘要

Peculiarities of the temperature isotope effect in a BCStype theory describing the exchange and phonon mechanisms of Cooper pairing in a system of strongly correlated electrons are considered. The elec tron–phonon interaction constant is determined from the fitting of the calculated value of the isotopeeffect index to the observed value with the parameters of La2 – xSrxCuO4 obtained from ab initio calculations. The value of this constant indicates that the contribution from the traditional pairing mechanism to the supercon ducting state is of the same order of magnitude as the contribution from the magnetic mechanism.