Evidence for a second one-dimensinal set of states shedding light on the normal phase of high Tc superconductors

We have identified a set of electronic states with a one-dimensional dispersion in the Γ=(0,0) to M1=(π,0) direction crossing the Fermi surface at one point kF=0.2±0.03π by angle-resolved photoemission. The one-dimensional character of these electronic states is demonstrated by missing dispersion along the orthogonal direction, observed in energy-distribution curves, and by k-space mapping of the Fermi surface, using angle scanning photoemission. The observed electronic states beyond the well-known large Fermi surface provoke the models based on charge and spin ordering in the CuO2 plane of high-Tc superconductors.