MUON SPIN ROTATION STUDY OF THE CORRELATION BETWEEN T(C) AND N(S)/M-ASTERISK IN OVERDOPED TL2BA2CUO6+DELTA

The muon spin depolarization rate sigma was measured in overdoped Tl2Ba2CuO6+delta. Sigma(T --> 0) was found to decrease proportional to the superconducting transition temperature T(c) as doping delta is increased. In the framework of the clean-limit London model, sigma(0) is similar to lambda-2 is similar to n(s)/m*, this implies that the depression of T(c) by overdoping is associated with a decrease of the superconducting condensate density n(s) in spite of the increasing normal-state carrier density. This can be largely accounted for in terms of strong pair breaking, which depresses both the condensate density and T(c) with increased doping.