A deeper look into iron selenide.

Abstract

Superconductivity In the past 10 years, iron-based superconductors have created more puzzles than they have helped resolve. Some of the most fundamental outstanding questions are how strong the interactions are and what the electron pairing mechanism is. Now two groups have made contributions toward resolving these questions in the intriguing compound iron selenide (FeSe) (see the Perspective by Lee). Gerber et al. used photoemission spectroscopy coupled with x-ray diffraction to find that FeSe has a very sizable electron-phonon interaction. Quasiparticle interference imaging helped Sprau et al. determine the shape of the superconducting gap and find that the electron pairing in FeSe is orbital-selective. Science , this issue p. [71][1], p. [75][2]; see also p. [32][3] [1]: /lookup/doi/10.1126/science.aak9946 [2]: /lookup/doi/10.1126/science.aal1575 [3]: /lookup/doi/10.1126/science.aan2657