Orbital-selective correlation and nematicity in iron-based superconductors

There is an expanding recognition that orbital-selective electron correlation plays a crucial role in understanding the properties of the iron-based superconductors [1,2]. In this talk, I will survey the theoretical developments on this subject, focusing on the orbital-selective Mott physics [3,4] which has been recently extensively studied, and its influence on the electronic bandstructure. I will then address the interplay between the orbital-selective correlation and electronic nematicity in iron selenide FeSe [5], and more generally, discuss how the nematic order and anisotropic fluctuations are understood in terms of strong electron correlations [6-8]. Implications of these results for the superconductivity will be discussed.

[1] R Yu, H Hu, E M. Nica, J-X Zhu, Q Si, arXiv:2007.00181.
[2] Q Si, R Yu and E Abrahams, Nature Rev. Mater. 1, 16017 (2016).
[3] R Yu, Q Si, Phys. Rev. B 96, 125110 (2017).
[4] R Yu, Q Si, Phys. Rev. Lett. 110, 146402 (2013).
[5] R Yu, J-X Zhu, Q Si, Phys. Rev. Lett. 121, 227003 (2018).
[6] R Yu, Q Si, Phys. Rev. Lett. 115, 116401 (2015).
[7] W-J Hu, H-H Lai, S-S Gong, R Yu, E Dagotto, Q Si, Phys. Rev. Research 2, 023359 (2020).
[8] C Liu, X Lu, P Dai, R Yu, Q Si, Phys. Rev. B 101, 024510 (2020).