The Phenomenology of Iron Pnictides Superconductors Explained in the Framework of s-Wave Three-Band Eliashberg Theory

摘要

The s-wave three-band Eliashberg theory can simultaneously reproduce the experimental critical temperatures and the gap values of the superconducting materials LaFeAsO_(0,9)F_(0.1), Ba_(0.6) Ka_(0.4) Fe_2As_2 and SmFeAsO_(0.8)F_(0.2) as 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).