Symmetry classification and phenomenology of paired states in iron based superconductors

We use the symmetry adapted low energy theory to classify the superconducting states in iron based materials with only hole, or only electron, pockets. In addition, the low energy effective theory is used to study pairing mechanisms which would stabilize the various states, as well as their phenomenology. The combined role of Hund's coupling and spin-orbit interactions will be highlighted as a possible way to overcome the detrimental effects of intra-orbital repulsion in achieving Cooper pairing.