THE NATURE OF THE OVERDOPED STATE IN HIGH T-C SUPERCONDUCTORS

We correlate the non-monotonic doping dependence of the penetration de pth lambda obtained on La2-xSrxCuO4 thin films, with the doping depend ence of the Cu-63 Knight shift K-s perpendicular to and the electronic specific heat coefficient gamma obtained on bulk compounds. These dat a suggest that the increase of lambda in the overdoped regime is relat ed to a decrease of the superfluid density and that the carriers induc ed beyond optimum doping do not condense into pairs, but contribute to decrease the superfluid density which was present at optimum doping.