Suppression of the superconducting condensate in the high-T-c cuprates by Zn substitution and overdoping: Evidence for an unconventional pairing state

By muon spin rotation we studied the depression in condensate density, n(s) by Zn substitution in underdoped, optimal-doped, and overdoped Ti0.8Ca0.2Ba2(Cu1-yZny)(3)O-7-delta. The rapid initial decrease of n(s) is inconsistent with s-wave pairing and magnetic scattering but points towards a d-wave pairing state with nonmagnetic scattering in the unitarity limit irrespective of the doping state. A similar conclusion is inferred from the depression of T-c and n(s) with overdoping in the pure compounds where pair breaking appears to be associated with increasing three dimensionality.