Superconductivity Fluctuations in a One-dimensional Two Band Electron-Phonon Model with Strong Repulsive Interactions

Abstract

We study a one-dimensional, two band model with short range electron-electron repulsions (onsite $U$ and nearest-neighbour $V$ terms) and electron-phonon coupling. We show that there is a region of $U$,$V$ and band filling in which singlet superconductivity fluctuations are dominant. This region is absent without electron-phonon interactions and includes large values of $U$,$V$.