Nematic Electronic Order in Iron Superconductors The properties of many high-temperature superconductors vary strongly as the composition of a doping element changes, and at sufficient under- or overdoping, other phases with different types of electronic ordering can form. Chuang et al. (p. 181 ; see the Perspective by Fradkin and Kivelson ) use scanning tunneling microscopy techniques to probe the electronic structure of an underdoped compound in the iron superconductor family, Ca(Fe 1− x Co x ) 2 As 2 . They observed periodic nanostructures oriented along Fe–Fe bonds that exhibit an electronic ordering related to ordering seen in nematic liquid crystals.

Nematic Electronic Structure in the “Parent” State of the Iron-Based Superconductor Ca(Fe 1– x Co x ) 2 As 2