Superconductivity and Peierls instability in coupled linear chain systems

Abstract

We study the superconducting transition temperature ( T c ) and the Peierls instability temperature ( T p ) using Eliashberg type equations for both T c and T p self consistently with finite interchain coupling. We show that T c > T p below a critical electron-phonon coupling constant which depends on the bare phonon frequency. This determines an upper bound on T c so that for higher transition temperatures T p > T c and superconductivity is unlikely. Higher values of T c are possible if the interchain coupling is increased above a critical value where the Peierls instability is suppressed.