Angle-resolved photoemission study of untwinned (formula presented) undoped (formula presented) plane and doped (formula presented) chain

We have performed an angle-resolved photoemission study on untwinned (Formula presented) which has low resistivity but does not show superconductivity. We have observed a dispersive feature with a band maximum around (Formula presented) indicating that this band is derived from the undoped (Formula presented) plane. We have observed another dispersive band exhibiting one-dimensional character, which we attribute to signals from the doped (Formula presented) chain. The overall band dispersion of the one-dimensional band agrees with the prediction of the (Formula presented) model calculation with parameters relevant to cuprates except that the intensity near the Fermi level is considerably suppressed in the experiment.