Cooper like paring and energy gap induced by ion electronic   polarizability
  We explore the possibility that the ionic electron polarizabilities of the oxygen ions in the cuprates and the bismutates and the polarizabilities of As and Se ions in the iron pnictides contribute to charge carrier pairing leading to high Tc superconductivity. Using the fact that the ionic polarization response to a change in the electric field is practically instantaneous we find, that the inter carrier electrostatic potential is attractive in a limited distance range. This potential is used to calculate quantum mechanically the cooper-like pairing energy and wavefunction and the gap energy showing they are consistent with pairing and gap energies of high Tc superconductors. Qualitative considerations suggest that this model may explain a number of important features of high Tc superconductors. 
Yizhak Yacoby and Yakov Girshberg
cond-mat.supr-con