Triplet pairing, orbital selectivity, and correlations in iron-based superconductors

We use a slave-boson approach to study the band renormalization and pair susceptibility in the normal state of iron-based superconductors in presence of strong Coulomb repulsion and Hund's interaction. Our results show orbital selectivity toward localization of $xy$ orbitals and its interplay with superconductivity. We also compare the recently proposed triplet resonating valence bond (tRVB) theory of superconductivity in iron-based superconductors with the more conventional ${s}_{\ifmmode\pm\else\textpm\fi{}}$ pairing. We show that both favor a superconductivity when the $xy$ orbital is delocalized, but the tRVB superconductivity supports a second weaker dome when $xy$ orbital is localized.