Strong-coupling corrections in high-Tc superconductors

The problem of determining the normal-state specific-heat coefficient for high-Tc oxide superconductors is considered, and a method for empirically determining the strong-coupling corrections is proposed. This permits a direct estimate of, and other parameters from a few measured quantities, if isotropic Eliashberg theory is assumed to apply. On this basis, it appears that conventional electron-phonon strong coupling can account for the superconducting properties of La1.85Sr0.15CuO4 but not those of YBa2Cu3O7-. © 1989 The American Physical Society