Fig. 7: Variable temperature QPI and model calculations based on disordered d-wave superconductor.
From: Emergent normal fluid in the superconducting ground state of overdoped cuprates
a and b The calculated spectral function A(k, ω) at EF in the normal and superconducting states of underdoped cuprate. The superconducting A(k, ω) has residual excitation near the nodes with vanishing \({\varDelta }_{{{{\rm{SC}}}}}({{{\bf{k}}}})\), while the normal A(k, ω) displays a full Fermi surface. c and d In the overdoped regime, the A(k, ω) at EF in the superconducting state is highly similar to the normal state Fermi surface. e and f FT of the conductance maps g(q, 0 mV) in the UD-20K sample taken at 5 and 23 K, respectively. The QPI pattern in the superconducting state is mainly located near the nodal region, while in the normal state, higher intensity appears near the antinodal region due to thermally excited quasiparticles. g FT of the conductance maps g(q, 0 mV) in the OD-15K sample at 23 K, which is nearly identical to that at 5 K shown in Fig. 3g. The Brillouin zone boundaries and lattice wavevector are marked by white lines and red points. h Angle dependence of the zero-bias QPI intensity below and above Tc for the UD-20K and OD-15K samples, revealing the strong contrast in the underdoped and overdoped regimes.
