Quasilocal structural excitations in the lattice of high-T_csuperconductors

Abstract

A model of a superconductor with structural lattice instability characterised by local structural excitations (LSE) is considered. On the basis of the double-time Green functions Eliashberg-type equations are obtained, and the superconducting transition temperature Tc is calculated. It is shown that an additional electron coupling due to LSE can greatly enhance Tc unless the lattice structural transformation appears.