Impurity scattering effects in STM studies of high-Tc superconductors

Recent STM measurements have observed many inhomogeneous patterns of the local density of states on the surface of high-T-c cuprates. As a first step to study such disordered strong correlated systems, we use the BdG equation for the t-t'-t ''-J model with an impurity. The impurity is taken into account by a local potential or local variation of the hopping/exchange terms. Strong correlation is treated by a Gutzwiller mean-field theory with local Gutzwiller factors and local chemical potentials. it turned out that the potential impurity scattering is greatly suppressed, while the local variation of hoppings/exchanges is enhanced. (C) 2008 Elsevier Ltd. All rights reserved.