Unconventional superconductivity in iron-based superconductors in a three-band model

Abstract

Iron-based superconductors exhibit features of systems where the Fulde-Ferrell-Larkin-Ovchinnikov phase, a superconducting state with non-zero total momentum of the Cooper pairs, is actively sought. Experimental and theoretical evidence points strongly to the Fulde-Ferrell-Larkin-Ovchinnikov phase in these materials above the Pauli limit. In this article we discuss the ground state of iron-based superconductors near the critical magnetic field and the full h-T phase diagram for pnictides in case of intra-band pairing, in a three-band model with s± symmetry.