Evidence of doping-dependent pairing symmetry in cuprate superconductors

Abstract

The directional and spatially resolved quasiparticle tunneling spectra in optimally doped yttrium superconductors were studied. Three optimally doped single crystals of the compound were used to derive the doping dependence of the pairiig symmetry, pairing potential, and spatial homogeneity. Results of the experiment revealed microscopic spatial modulations; strong scattering near the impurity sites; and global suppression of pairing potential.