Extended Data Fig. 9: Possible theoretical scenarios for the PDW state at the domain wall.
From: Pair density wave state in a monolayer high-Tc iron-based superconductor
a, Schematic of the PDW state at the domain wall. \({\varDelta }_{{\rm{SC}}}^{\mathrm{1,2}}\) and \({\varDelta }_{{\rm{SC}}}^{{\rm{DW}}}\) represent the zero-momentum superconductivity in the domains (1 and 2) and at the domain wall, respectively. b, Illustration of the finite center of mass momentum, equal-spin pairing in the presence of only Rashba SOC. \({\rm{\langle }}{c}_{{\bf{k}},\uparrow }{c}_{-{\bf{k}}+{\bf{Q}},\uparrow }{\rm{\rangle }}\) and \({\rm{\langle }}{c}_{-{\bf{k}},\downarrow }{c}_{{\bf{k}}-{\bf{Q}},\downarrow }{\rm{\rangle }}\) are equal-spin pairing order parameters where one spin sector carries momentum +Q and the other spin sector –Q. c, Illustration of the finite center of mass momentum equal-spin pairing in the presence of both Rashba and Dresselhaus SOC. In this case, the triplet equal-spin pairing order parameters \({\rm{\langle }}{c}_{{\bf{k}},\sigma }{c}_{-{\bf{k}}+{\bf{Q}},\sigma }{\rm{\rangle }}\) and \({\rm{\langle }}{c}_{-{\bf{k}},\sigma }{c}_{{\bf{k}}-{\bf{Q}},\sigma }{\rm{\rangle }}\) can have both spin components (σ), i.e., each equal-spin pairing sector carries both nonzero momentum +Q and –Q, giving rise to the equal-spin pairing PDW state. d,f, Calculated tunneling density of states ρi(ω) with i the site index, for two examples with Q = 2π/12 (d) and Q = 2π/4 (f), where the insets show the zoom-in feature around the coherent peaks. e,g, The spatial modulations of the superconducting gap extracted from the corresponding coherence peak positions for the Q = 2π/12 (e) and Q = 2π/4 (g).
