Evidence for a second one-dimensional 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 Gamma=(0,0) to M-1 =(pi,0) direction crossing the Fermi surface at one point k(F)=0.2+/-0.03 pi 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-T-c superconductors.