Study of layered superconductors in the framework of an electron–phonon coupling mechanism

Abstract

We summarize a number of recent developments in the study of layered superconductors using the electron–phonon Eliashberg theory. The critical temperature of layered superconductors is calculated using the Eliashberg theory. The influence of nonadiabaticity effects on the critical temperature in layered superconductors is considered. The influence of Coulomb repulsion on the critical temperature is investigated in the case of an arbitrary thicknesses of conducting layers. Bardeen–Cooper–Schrieffer (BCS) equations for layered superconductors are used for the calculation of a specific heat jump, which is smaller than in the case of an isotropic BCS theory. The plasmon spectrum of layered superconductors with an arbitrary thicknesses of conducting layers is calculated. The influence of fluctuations in the order parameter phase on the critical temperature of layered superconductors is studied using the Ginzburg–Landau functional for the free energy. The results are shown to be in qualitative agreement with some experimental data for cuprate superconductors and recently discovered MgB2.