Electron correlation and spin dynamics in iron pnictides and chalcogenides

Rong Yu, Qimiao Si*, Pallab Goswami, Elihu Abrahams

*Corresponding author for this work

Research output: Contribution to journalConference article

9 Scopus citations

Abstract

Superconductivity in the iron pnictides and chalcogenides is closely connected to a bad-metal normal state and a nearby antiferromagnetic order. Therefore, considerable attention has been focused on the role of electron correlations and spin dynamics. In this article, we summarize some key experiments that quite directly imply strong electron correlations in these materials, and discuss aspects of the recent theoretical studies on these issues. In particular, we outline a w-expansion, which treats the correlation effects using the Mott transition as the reference point. For the parent systems, it gives rise to an effective J1-J2 model that is coupled to the itinerant electrons in the vicinity of the Fermi energy; this model yields an isoelectronically-tuned quantum critical point, and allows a study of the distribution of the spin spectral weight in the energy and momentum space in the paramagnetic phase. Within the same framework, we demonstrate the Mott insulating phase in the iron oxychalcogenides as well as the alkaline iron selenides; for the latter system, we also consider the role of an orbital-selective Mott phase. Finally, we discuss the singlet superconducting pairing driven by the short-range J1-J2 interactions. Our considerations highlight the iron pnictides and chalcogenides as exemplifying strongly-correlated electron systems at the boundary of electronic localization and itinerancy.

Original languageEnglish (US)
Article number012025
JournalJournal of Physics: Conference Series
Volume449
Issue number1
DOIs
StatePublished - Jan 1 2013
Event10th International Conference on Materials and Mechanisms of Superconductivity, M2S 2012 - Washington, DC, United States
Duration: Jul 29 2012Aug 3 2012

ASJC Scopus subject areas

  • Physics and Astronomy(all)

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