The Triplet Resonating Valence Bond State and Superconductivity in Hund's Metals: III Phenomenology in iron based superconductors.

Based on the triplet Resonating Valence Bond concept introduced in the previous two talks, I will discuss the prospects and signatures of this theory in the context of iron based superconductors. I will explicitly concentrate on the spin-triplet, orbital antisymmetric pairing state as derived in part II and on four experimental techniques of fundamental interest: (1) nuclear magnetic resonance, (2) neutron scattering, (3) tunneling spectroscopy, (4) scanning Josephson tunneling microscopy. First, I will demonstrate that this pairing state develops an anisotropic, partial suppression of the Knight shift and discuss existing experimental data on single crystals. Second and third, I will demonstrate that the relative sign between triplet d-vectors of electron and hole pockets crucially affects finite frequency spin-susceptibility and local density of states. I will discuss the consequences thereof for key experimental observables, i.e. a sharp subgap spin-resonance and characteristic quasi-particle interference patterns, that previously were interpreted as evidence for s_+- pairing. Finally, I describe experimental signatures of the staggered order parameter in scanning Josephson microscopy.