Nematicity driven by hybridization in iron-based superconductors

2013/02/28 by Valentin Stanev, P. B. Littlewood, Peter B. Littlewood
Materials Science · Physics and Astronomy · #Iron-based superconductors research #Physics of Superconductivity and Magnetism #Rare-earth and actinide compounds #cond-mat.str-el #cond-mat.supr-con

paper · pdf · doi:10.1103/physrevb.87.161122

published as Phys. Rev. B 87, 161122(R) (2013) · 5 pages, 3 figures, new references added, replaced Fig. 1, fixed several typos

arxiv created 2013/04/17 · openalex publication_date 2013/04/30 · arxiv updated 2013/05/22 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05

Abstract

In this Rapid Communication, we study an effective model for the normal state of iron-based superconductors. It has separate but interacting itinerant and localized degrees of freedom, originating from the d_xz and d_yz and from the d_xy iron orbitals, respectively. At low temperatures, below a mean-field phase transition, these different states condense together in an excitonic order parameter. We show that, at even lower temperatures, after another phase transition, this ordered state can spontaneously break the C₄ lattice symmetry and become nematic. We propose this mechanism as an explanation of the tendency towards nematicity observed in several iron-based compounds.

Citations

• Symmetry-breaking orbital anisotropy observed for detwinned Ba(Fe 1- x Co x ) 2 As 2 above the spin density wave transition
• Fermi surface dichotomy of the superconducting gap and pseudogap in underdoped pnictides