Electronic structure of La2-xSrxCuO4 in the vicinity of the superconductor-insulator transition

We report on the result of angle-resolved photoemission study of La2-xSxCuO4 (LSCO) from an optimally doped superconductor (x=0.15) to an antiferromagnetic insulator (x=0). Near the superconductor insulator transition x similar to 0.05, spectral weight is transferred with hole doping between two coexisting components, suggesting a microscopic inhomogeneity of the doped-hole distribution. For the underdoped LSCO (x less than or equal to 0.12), the dispersive band crossing the Fermi level becomes invisible in the (0,0)-(pi,pi) direction unlike Bi2Sr2CaCu2O8+gamma These observations may be reconciled with the evolution of holes;in the insulator into fluctuating stripes in the superconductor.