Effect of Anderson impurities with a strong local electron-phonon coupling on the superconducting transition temperature
Mal'shukov A. G.
Quasistationary impurity electronic states which are coupled with local lattice vibrations are analyzed in the Anderson model. The theory of a Fermi liquid is usee to calculate Tc. If the coupling constant describing the coupling of the impurity states with the vibrations is sufficiently large, even a small impurity concentration may cause a significant increase in Tc. The isotopic effect does not correspond to the BCS theory. Some consequences of the model for high-temperature superconductors are discussed.