DIPOLON MECHANISM OF HIGH-TC SUPERCONDUCTORS

The collective oscillations of the crystal field generated electronic dipoles (''dipolons'') as a possible new excitation responsible for the electron-electron pairing mechanism in the high T-c superconductivity have been proposed. The calculated results of electronic dipoles, the dispersion relations and density of states of dipolons in YBa2Cu3O7 have been given. The absence of inversion symmetry and the high polarizablility of the atoms such as oxygens in high T-c superconductors are found to be necessary for the existence of the dipolons. There are good consistency between the existence of high T-c superconductivity and the presence of dipolons in conducting planes of the high T-c superconductor crystals. The explaining the other important properties via dipolon mechanism such as the pressure effect and the isotope effect observed in the high T-c superconductors has been discussed.