The phenomenology of iron pnictides superconductors explained in the framework of s-wave three-band eliashberg theory

Abstract

The s-wave three-band Eliashberg theory can simultaneously reproduce the experimental critical temperatures and the gap values of the superconducting materials LaFeAsO0. 9F 0. 1, Ba 0. 6 K 0. 4Fe2As2and SmFeAsO0. 8F 0. 2as exponent of the more important families of iron pnictides. In this model the dominant role is played by interband interactions and the order parameter undergoes a sign reversal between hole and electron bands (s ± -wave symmetry). The values of all the gaps (with the exact experimental critical temperature) can be obtained by using high values of the electron-boson coupling constants and small typical boson energies (in agreement with experiments). Copyright © 2010 G. A. Ummarino.