2008/09/21 by С. Г. Овчинников, Ovchinnikov, S. G., E. I. Shneyder +1
Earth and Planetary Sciences · Materials Science · Physics and Astronomy · #FOS: Physical sciences #High-pressure geophysics and materials #Magnetic and transport properties of perovskites and related materials #Physics of Superconductivity and Magnetism #Strongly Correlated Electrons (cond-mat.str-el) #Superconductivity (cond-mat.supr-con)
paper · pdf · doi:10.48550/arxiv.0809.3585
openalex publication_date 2008/09/21 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/01
Strong electron correlations are responsible both for the insulator ground state of undoped La2CuO4 and strong antiferromagnetic coupling J between neighbouring spins. We consider magnetic mechanism of superconducting pairing in the effective low energy t - t' - t" - J^* model with all parameters calculated \it ab initio. Interaction of strongly correlated electrons with different phonon modes is also incorporated. In a BCS type theory the dx2 - y2 gap is given by a sum of magnetic and phonon contributions. The phonon coupling parameter λ= f(x)G, where G is a combination of bare electron-phonon couplings for all modes and the function f depends on the hole concentration x due to strong electron correlations. 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 Tc work together and are of the same order of magnitude.