Variations of Pairing Potential and Charge Distribution in Presence of a   Non-magnetic Impurity
  Using an attractive Hubbard model we examine spatial variations of superconducting order parameter and local charge on a two dimensional lattice.   For various band filling we show the effect of destruction of the order parameter around a non-magnetic impurity. In case of a half-filled system such destruction is accompanied by appearance of characteristic charge variations around the impurity with an isotropic distribution. 
Grzegorz Litak