Event Details

Electron correlation effects give rise to a variety of emergent phenomena in quantum materials-high temperature superconductivity, electronic nematicity, Mott insulating phase, and magnetism. In the multi-orbital iron-based superconductors, electronic correlations are manifested in an orbital-dependent way, realizing all of the above in different parameter regimes. In this talk, I will present experimental evidence from angle-resolved photoemission spectroscopy on systematic evolution of multi-orbital correlation effects across the iron-based superconductor material basis. In particular, I will present spectroscopic evidence for tendencies towards an orbital-selective Mott phase in the iron-chalcogenides as tuned via both temperature and isovalent substitution, as manifested in the vanishing of coherent quasiparticle spectral weight, divergence of effective mass, and reorganization of low energy electronic states, revealing the strong presence of correlation effects in this class of multi-orbital superconductors.