Electronic structure ofLa2−xSrxCuO4in the vicinity of the superconductor-insulator transition

We report on the result of angle-resolved photoemission study of ${\mathrm{La}}_{2-x}{\mathrm{Sr}}_x{\mathrm{CuO}}_4$ (LSCO) from an optimally doped superconductor $\mathrm{}(x=0.15\mathrm{})\mathrm{}$ to an antiferromagnetic insulator $\mathrm{}(x=0\mathrm{}).$ Near the superconductor-insulator transition $x\sim 0.05,$ spectral weight is transferred with hole doping between two coexisting components, suggesting a microscopic inhomogeneity of the doped-hole distribution. For the underdoped LSCO $(x<~0.12),$ the dispersive band crossing the Fermi level becomes invisible in the $\mathrm{}(0,0)\mathrm{}-(\pi ,\pi )$ direction unlike ${\mathrm{Bi}}_2{\mathrm{Sr}}_2{\mathrm{CaCu}}_2{\mathrm{O}}_{8+y}.$ These observations may be reconciled with the evolution of holes in the insulator into fluctuating stripes in the superconductor.