Fig. 3
From: Percolative nature of the direct-current paraconductivity in cuprate superconductors
Schematic representation of the superconducting site percolation model, as a two-dimensional cross section of the full three-dimensional model (upper row). Dark red patches are superconducting with vanishing resistance, whereas light gray patches have nonzero normal-state resistance. As per Eq. (1), the fraction of superconducting patches is simply obtained by integrating the local gap (i.e., Tc) distribution function, taken to be a Gaussian for simplicity (lower row). Note that for a typical three-dimensional percolation model the critical fraction is ~0.3
