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Center for Nonlinear Studies |
High temperature superconductivity in the iron based systems has commanded much attention since its discovery five years ago. There is by now an emerging consensus that electron correlations play an essential role in these materials. The correlation effects were implicated from early on by the bad metal behavior of the iron pnictides. They have been further highlighted by the more recently discovered alkaline iron selenide superconductors, whose parent compounds are Mott insulators. In this talk, I will discuss these and related aspects of the electron-correlation physics in the iron pnictides and selenides. Particular attention will be paid to our recent theoretical studies in multi-orbital Hubbard models, which have led to an orbital-selective Mott phase in the alkaline iron selenides. Evidence for such a phase has been obtained by angle-resolved photoemission experiments. Some broader implications of these results for the magnetism and superconductivity will be discussed.
Host: Jianxin Zhu