μSR study of impurity effects on the Cu-spin fluctuations in the overdoped regime of La_2-xSr_xCu_1-yZn_yO₄

Zero-field muon-spin-relaxation measurements have been carried out for La_2-xSr_xCu_1-yZn_yO₄ (LSCO) with y = 0-0.10 in the overdoped regime up to x = 0.30, in order to investigate whether the dynamical stripe correlations are pinned and stabilized even for the overdoped LSCO or not. It has been found that the Zn-induced slowing down of the Cu-spin fluctuations is weakened with increasing x but takes place in the overdoped regime and disappears at x = 0.30. This suggests that the stripe-pinning model holds good in the whole superconducting regime of LSCO and that there is no quantum critical point at x ∼ 0.19.