The structure of the superconducting phase of iron-based superconductor KxFe2−ySe2 is difficult to determine because it coexists with an predominant insulating phase. Ding et al. identify the superconducting filaments that provide clues to the structure of the parent phase of superconductivity.
- Xiaxin Ding
- Delong Fang
- Hai-Hu Wen