Abstract

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.