Defect-induced Changes in the Spectral Properties of Bi2Sr2CaCu2O8+x: Angle-resolved Photoemission Study

We investigated the effects of disorder in Bi2Sr2CaCu2O8+x high temperature superconductor. We found that small defect densities already suppress the characteristic spectral signature of the superconducting state. The spectral line shape clearly reflects new excitations within the gap, as expected for defect-induced pair breaking.