Theoretical study of conventional superconductors

Abstract

The electron-electron interaction i.e. the study of electron-electron interaction among the two electrons in the cooper pairs under ambient and applied pressure is the motivation of this research work. The BCS theory is able to predict accurately the superconducting properties for weak coupling conventional superconductors but fails to predict accurately the superconducting properties like transition temperature (Tc) for strong coupling conventional superconductors. Eliashberg-Migdal formalism which happens to be the extension of BCS theory to strong coupling conventional superconductors has been successful in predicting the superconducting properties for strong coupling conventional superconductors. To study the electron-electron interaction Phonon dispersion relation, Eliashberg spectral function, Phonon DOS, superconducting transition temperature, average electron-phonon coupling constant and average logarithmic phonon frequency have been calculated both under ambient and applied pressures for AB3 (YSn3,YIn3, LaSn3) type materials. newline