Many-body calculation of the spatial extent of the wave-function of a   non-magnetic impurity in a d-wave high-temperature superconductor using the   t--J model
  Scanning tunneling microscopy (STM) by providing images of the effects of individual zinc-impurities in cuprate superconductors with unprecedented atomic-resolution offers a stringent test to models of correlated fermions for high-temperature superconductors. Using a t-J model supplemented by Variational Monte Carlo many-body techniques, the spatial dependence of the hole density and of the valence bond and superconducting pairing amplitudes around the impurity are computed. A cross-shaped four-fold symmetric structure very similar to the observed STM observation is found, giving strong credit to the model. 
Manuela Capello and Didier Poilblanc