DIELECTRIC-PROPERTIES AND ELECTRON SPECTRUM OF THE MULLER MODEL IN THE HIGH-TEMPERATURE SUPERCONDUCTIVITY THEORY

The paper is devoted to the investigation of the single-electron excit ation spectrum, effective exchange interaction and dielectric suscepti bility of the Muller model for high-temperature superconductivity. It is shown that the interaction with the anharmonic vibration mode leads to the additional splitting of the electron bands and their narrowing . The sign of the effective exchange interaction between electrons dep ends on the local state of the vibration subsystem. The electron and p seudospin (lattice) contributions to the transverse dielectric suscept ibility are investigated.