Electron Localization in La_{2-x}Sr_xCuO_4 and the Role of Stripes

Abstract

The normal-state in-plane resistivity (\rho_{ab}) is measured in lightly Zn-doped La_{2-x}Sr_xCuO_4 (LSCO) crystals with 0.06 \leq x \leq 0.17 to systematically study the localization behavior. It is found that the localization temperature, T_{loc}, where \rho_{ab}(T) turns from metallic (d\rho_{ab}/dT>0) to insulating (d\rho_{ab}/dT<0), shows an anomalous enhancement at x=0.12. Intriguingly, the doping dependence of T_{loc} in Zn-doped LSCO is found to be similar to that of Zn-free LSCO where superconductivity is suppressed by a high magnetic field. This suggests that the mechanism of the localization is the same in lightly Zn-doped LSCO and in Zn-free LSCO under magnetic field, and in both cases it is probably caused by the freezing of the electrons into an inhomogeneous state, which leads to the spin stripes at low temperatures.