A Possible Fundamental Theory of Cooper Pair Formation in Unconventional Superconductivity

Abstract

The successful application of the electron-phonon interaction (EPI) mechanism in formulating the Bardeen-Cooper-Schrieffer (BCS) theory of superconductivity is among the most outstanding intellectual achievements in theoretical physics because of the successful application of the theory to the conventional superconducting materials. Therefore, its unsuccessful application to the nonconventional superconducting materials has led to the search for new theories which generalized it, include an interplay with other mechanisms or are formulated from non -EPI mechanisms. We observe in this current study that to achieve a generalized theory of superconductivity, there is need to first developed a quantitative structure model of the Cooper pair formation (CPF) in line with the formulation of the molecules in nature which has given birth to hadronic mechanics. This generalized formulation is the iso-superonductivity model which is based on the observation that the Cooper pair of the standard BCS model may have a nonlocal-nonhamiltonian structure equivalent to the strong interaction ("hadronic" mechanics (HM)) structure of the neutral pion, as compressed positronium atom at short distances (< 1 F  10 -13 cm. The equivalent but approximate description at large distances (> 1 F) is by the quantum mechanical superexchange interaction. This generalized CPF has been used to successfully explain the high-T c superconductivity in the cuprates as well as to account for the transition temperatures of these materials. It is also used to account for the high-T c iron based superconducting materials.