In-plane Cu-O bond distribution and charge inhomogeneity in La2-xSrxCuO4 as a function of doping.

We report in-plane Cu-O atomic displacements as a function of doping in the La2-xSrxCuO4 system, determined by polarized Cu K-edge extended x-ray absorption fine structure measurements. We find a wide distribution of the Cu-O bonds showing a single peak asymmetric function for the system at low doping, which gets two peak function for the underdoped and optimally doped superconducting phases before turning to a single peak function for the overdoped phase. The results provide a direct evidence of critical local lattice fluctuations for an optimum transition temperature in the superconducting phases hosting quantum stripes. [ABSTRACT FROM AUTHOR]