EVIDENCE FOR A STRIPED PHASE OF HIGH T-C SUPERCONDUCTOR AT THE FERMI-SURFACE

A complete Fermi surface in the normal state of superconducting Bi2Sr2 CaCu2O8+delta at the optimum doping (T-c = 91 K) has been measured by angle scanning photoemission spectroscopy using synchrotron radiation. The Fermi surface reveals broken segments and hot spots of high photo intensity along lines of k(y) = n.0.23 Angstrom(-1) in the (pi, pi) di rection, The pseudogap observed at (pi, 0) in underdoped materials is one of this missing segments. The results indicate the presence of cha racteristic subbands of a superlattice of quantum stripes. This is for med by an ordered array of similar to 14 Angstrom large stripes.