We show that electronic Raman scattering affords a window into the essential properties of the pairing potential of iron-based superconductors. In BaKFeAs we observe band dependent energy gaps along with excitonic Bardasis-Schrieffer modes characterizing, respectively, the dominant and subdominant pairing channel. The symmetry of all excitons allows us to identify the subdominant channel to originate from the interaction between the electron bands. Consequently, the dominant channel driving superconductivity results from the interaction between the electron and hole bands and has the full lattice symmetry. The results in RbFeSe along with earlier ones in Ba(FeCo)As highlight the influence of the Fermi surface topology on the pairing interactions.

生成讲解博客的中文版本

生成AI智能校验的中文版本