Figure 1

(a) Schematic plot of the unfolded FS. (b) $k_z=0$ slice of the 122 band structure given in Ref. 33. The dominant orbital weights along the $e$ and $h$ pockets are highlighted in (a). The patches along pockets are enumerated counterclockwise, starting at each pocket with the patch indicated by a dot. The number of patches with electron pockets is 80, and without it decreases to 48.Reuse & Permissions

Figure 2

Representative scenarios of the FS (unfolded Brillouin zone) and instability eigenvalue flows for chemical potential and electron concentration per iron $\mu =-0.12$, $n_{\mathrm{el}}=5.913$ (a), $\mu =-0.22$, $n_{\mathrm{el}}=5.663$ (b), and $\mu =-0.32$, $n_{\mathrm{el}}=5.346$ in (c). The hole doping of our model calculation in (c), while exceeding the experimental setup $n_{\mathrm{el}}=5.5$, best matches the FS profile from ARPES [32]. The dominant and subdominant scatterings in the Cooper channel are highlighted in (a1)–(c1) by full and dashed arrows. The color contours along the FS label the dominant orbital weights [inset (a1)]. The leading eigenvalue flow of the ordering channel for different Fermi instabilities [charge density wave (CDW), Pomeranchuk (PI), spin density wave (SDW), and superconductivity (SC)] are plotted in (a2)–(c2) versus the IR cutoff FRG flow parameter $\Lambda$. For (a) and (b) we find $s^{\pm }$ as the leading Fermi instability. For (c) we observe a leading $d$-wave instability.Reuse & Permissions

Figure 3

(a) Form factor of the leading SC instability of scenario Fig. 2b, plotted versus the patching index of the Fermi pockets according to Fig. 1a. (b) Eigenvalues of the orbital decomposition of the SC form factor in (a). The ratio of the values label the relative importance of the orbital scattering channel $V(a,a\to b,b)c_{a\uparrow }{c}_{a\downarrow }{c}_{b\downarrow }^{†}{c}_{b\uparrow }^{†}$.Reuse & Permissions

Figure 4

(a) Form factor of the leading SC instability of the strongly hole-doped scenario Fig. 2c, plotted versus the patching index of the FS according to Fig. 1a. (b) Eigenvalues of the orbital decomposition of the SC form factor in (a). We find a extended $d$-wave form factor. The nodal points are given along the main diagonal of the Brillouin zone; i.e., the form factor of the inner $h$ pocket, for example, crosses zero between the patches $(2,3)$, $(6,7)$, $(10,11)$, and $(14,15)$.Reuse & Permissions