The Fermi surface of a high-T-c superconductor at optimum doping by angle-scanning photoemission spectroscopy

Evidence for charge fluctuations in diagonal stripes coupled with electrons at the Fermi surface is reported. Superconducting Bi2Sr2CaCu2O8+delta at optimum doping (T-c = 91 K) has been studied by angle-scanning photoemission spectroscopy using synchrotron radiation. The Fermi surface shows broken segments and hot spots of high spectral weight. The suppression of spectral weight in the pseudogap region near M = (pi,0) is shown to be due to a charge modulation with wavevector q(1) approximate to 0.4(pi,pi) associated with the superlattice of one-dimensional (1D) diagonal stripes or 1D charge-density waves. These stripes coexist with collective spin and charge fluctuations in the vertical direction.