STM of quasiparticle scattering resonances in Bi(2)Sr(2)zCaCu(2)O(8+delta)

High-resolution, low-temperature scanning tunneling microscopy and spectros copy on Bi2Sr2CaCu2O8+delta reveal the existence of large numbers of scatte ring centers in this material. The spatial and spectroscopic characteristic s of these features are consistent with theories of quasiparticle scatterin g from atomic scale impurities in a d-wave superconductor. These characteri stics include breaking of local particle-hole symmetry and an inverse squar e dependence of their local density-of-states (LDOS) on distance from the s cattering center. Furthermore, these observations identify a source for the anomalously high levels of low-energy excitations in Bi2Sr2CaCu2O8+delta a t low-temperatures. (C) 2000 Elsevier Science B.V. All rights reserved.