Suppression of superconductivity in high-Tc cuprates due to nonmagnetic impurities: Implications for the order parameter symmetry
Department of Physics,
Bilkent University, Bilkent, 06533 Ankara, Turkey
Corresponding author: a email@example.com
Published online: 15 July 1999
We studied the effects of nonmagnetic impurities on high-temperature superconductors by solving the Bogoliubov-de Gennes equations on a two-dimensional lattice via exact diagonalization technique in a fully self-consistent way. We found that s-wave order parameter is almost unaffected by impurities at low concentrations while -wave order parameter exhibits a strong linear decrease with impurity concentration. We evaluated the critical impurity concentration at which superconductivity ceases to be 0.1 which is in good agreement with experimental values. We also investigated how the orthorhombic nature of the crystal structure affects the suppression of superconductivity and found that anisotropy induces an additional s-wave component. Our results support -wave symmetry for tetragonal and -wave symmetry for orthorhombic structure.
PACS: 74.72.-h – High-Tc compounds / 74.62.Dh – Effects of crystal defects, doping and substitution / 74.20.-z – Theories and models of superconducting state
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 1999