Multiband s± Eliashberg theory and temperature-dependent spin-resonance energy in iron pnictide superconductors

The phenomenology of iron pnictide superconductors can be explained in the framework of a three-band s +/- wave Eliashberg theory with only two free parameters plus a feedback effect, i.e., the effect of the condensate on the antiferromagnetic spin fluctuations responsible for the superconductivity in these compounds. I have examined the experimental data of four materials, LaFeAsO1-xFx, SmFeAsO1-xFx, Ba1-xKxFe2As2, and Ba(FexCo1-x)(2)As-2, and I have found that it is possible to reproduce the experimental critical temperature and gap values in a moderate strong-coupling regime, lambda(tot) approximate to 1.7 - 2.0.