Superconducting vibronic interaction in model organic polymers which contain hetero atoms and triple bonds

Abstract

Ab initio quantum chemical calculations of the attractive force for superconductivity are performed by considering the vibronic interaction with an exact Hamiltonian. An electron pair can form momentarily by this force, and the values of the vibronic interactions could be criteria for designing a new polymer which would have a superconducting nature. The electronic states of the structural units of the polymers which contain hetero atoms (oxygen or nitrogen atoms) and triple bonds are compared with trans-polyacetylene which contains neither these atoms nor a triple bond. The strength of the vibronic interactions of these polymers are compared with trans-polyacetylene, and strong attractive interactions are found for these polymers. The vibronic mode specificity of the vibronic interactions are also investigated for these polymers. Finally the geometrical change of the polymer which has an acetylene bond (C-O-C) structure is discussed. By changing the C-O-C angle of this polymer, the energy differences between the molecular orbitais near the Fermi level become small. Therefore the scattering processes near the Fermi level are affected considerably and a strong attractive interaction is obtained for this polymer.