2012/10/31 by Rong Yu, Qimiao Si, Pallab Goswami +1
Materials Science · Physics and Astronomy · #Antiferromagnetism #Condensed matter physics #Electron #Electronic correlation #Fermi liquid theory #Hubbard model #Iron-based superconductors research #Mott transition #Pairing #Paramagnetism #Phase transition #Physics #Quantum critical point #Quantum mechanics #Quantum phase transition #Spin (aerodynamics) #Strongly correlated material #Superconductivity #cond-mat.str-el #cond-mat.supr-con
paper · pdf · doi:10.1088/1742-6596/449/1/012025
published as J. Phys.: Conf. Ser. 449, 012025 (2013) · v2. Discussion extended on several points, including the expected effect of the reduced/suppressed vacancy order on the spin spectral weight at temperatures above the Neel/structural transitions in the insulating alkaline iron selenides. 14 pages, 9 figures, to appear in the Proceedings of Materials and Mechanisms of Superconductivity Conference (M2S 2012, Washington D.C.)
arxiv created 2012/12/18 · openalex publication_date 2013/07/17 · arxiv updated 2014/08/08 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/06
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 J 1 - J 2 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 J 1 - J 2 interactions. Our considerations highlight the iron pnictides and chalcogenides as exemplifying strongly-correlated electron systems at the boundary of electronic localization and itinerancy.