Out-of-plane defects and nanoscale inhomogeneity in cuprate superconductors

Tamara Nunner

Department of Physics, University of Florida

In recent years high-resolution STM experiments on superconducting BSCCO-2212 have revealed the existence of nanoscale inhomogeneities in the electronic structure at biases near the superconducting energy gap. We theoretically investigate the relation of these inhomogeneities with disorder in the out-of-plane oxygen dopant atoms. Based on 1-impurity and many-impurity Bogoliubov-de Gennes calculations we argue that the main effect of the out-of-plane dopants is to modulate the pair interaction locally. Unlike conventional potential scattering the consideration of off-diagonal scattering can reproduce the experimentally observed relation between gap magnitude and height of the coherence peaks.