A. Y. Matsuura

Evolution of the electronic structure with doping in Bi2Sr2CaCu2O8+δ - Angle resolved photoemission results

Abstract We present experimental results showing that the electronic structure of the high Tc cuprate superconductors evolves from having large pieces of Fermi surface (FS) at high doping levels to small pieces of FS centered at (π/2,π/2) at low doping levels. The dramatic change in the FS occurs with only subtle changes in the electronic structure, which occur mostly near the (π,0) point of the Brillouin zone. We suggest that this evolution is intimately related to the evolution of the antiferromagnetic (AF) order with doping.

Band mapping of the model insulator Sr2CuO2Cl2—Dispersion of a single hole in an antiferromagnetic background

Abstract We report angle resolved photoemission measurements on Sr 2 CuO 2 Cl 2 , an insulating layered copper oxide. We map the energy-momentum dispersion of the highest energy band. We find that the width of this band is consistent with calculations based on variations of the Hubbard model. The dispersion in some directions and the position of the valence band maximum at ( π 2 , π 2 ) match predictions of the t − J model. However the overall shape of the band differs from these predictions. A comparison of our data with spectra previously reported on metallic samples leads to surprising new suggestions for the phenomenology of doping.