The generalized Hartree-Fock theory of nonmagnetic high-temperature superconductors

Abstract

The Eliashberg equations are generalized to apply to high-temperature superconductors without spin correlations. The generalization assumes any general electronic density of states. Consequently, it treats the Coulomb interaction dynamically, and takes into account the averaged momentum dependence of the self-energy and of the interactions. Unlike in the conventional Eliashberg equation, the bare Coulomb interaction yields a frequency-independent term in the renormalization function. This term breaks the symmetry of the self-energy, and changes the renormalization.