Imaging the effects of individual zinc impurity atoms on superconductivityin Bi2Sr2CaCu2O8+delta

Although the crystal structures of the copper oxide high-temperature superc onductors are complex and diverse, they all contain some crystal planes con sisting of only copper and oxygen atoms in a square lattice: superconductiv ity is believed to originate from strongly interacting electrons in these C uO2 planes, Substituting a single impurity atom for a copper atom strongly perturbs the surrounding electronic environment and can therefore be used t o probe high-temperature superconductivity at the atomic scale. This has pr ovided the motivation for several experimental(1-8) and theoretical studies (9-20). Scanning tunnelling microscopy (STM) is an ideal technique for the study of such effects at the atomic scale, as it has been used very success fully to probe individual impurity atoms in several other systems(21-25). H ere we use STM to investigate the effects of individual zinc impurity atoms in the high-temperature superconductor Bi2Sr2CaCu2O8+delta. We find intens e quasiparticle scattering resonances(26) at the Zn sites, coincident with strong suppression of superconductivity within similar to 15 Angstrom of th e scattering sites. Imaging of the spatial dependence of the quasiparticle density of states in the vicinity of the impurity atoms reveals the long-so ught four-fold symmetric quasiparticle 'cloud' aligned with the nodes of th e d-wave superconducting gap which is believed to characterize superconduct ivity in these materials.