Knowledge of the symmetry of the superconducting order parameter is essential to understand the origin of superconductivity itself. Studies on the recently discovered heavily doped Fe2Se2 now show that in these compounds the order parameter has a relatively simple symmetry compared with most other Fe-based superconductors, questioning again the generality of the results obtained so far.
- Y. Zhang
- L. X. Yang
- D. L. Feng
