Figure 3
From: Anisotropy of the superconducting gap in the iron-based superconductor BaFe2(As1-xPx)2
Superconducting gap anisotropy observed on the electron FSs around the X point in BaFe2(As1-xPx)2 (x = 0.30, Tc = 30 K) taken at hν = 40 eV.
(a) Fermi surface mapping using a circularly polarized light. The Fermi angle is defined so that the direction from X to Γ is θFS = 0. (b) EDCs at kF taken below Tc (T = 13 K) and compared with gold spectra. (c) (d) EDCs at kF taken below (T = 13 K) and above (T = 35 K) Tc for the inner and outer FSs. Vertical bars indicate the peak positions and the crossing energy between the spectra below and above Tc. (e) (f) Energy of the peak and the crossing point for the inner and outer FSs are plotted as a function of Fermi surface angle θFS. While the SC gap of the inner FS is highly anisotropic, a clear anisotropy is not identified in the outer FS. We could not obtain the signal of the outer band near the edge of the FS because its intensity is weak and merges with the inner band.
