Zinc Impurities in the 2D Hubbard model
  We study the two-dimensional Hubbard model with nonmagnetic Zn impurities modeled by binary diagonal disorder using Quantum Monte Carlo within the Dynamical Cluster Approximation. With increasing Zn content we find a strong suppression of d-wave superconductivity concomitant to a reduction of antiferromagnetic spin fluctuations. $T_c$ vanishes linearly with Zn impurity concentration. The spin susceptibility changes from pseudogap to Curie-Weiss like behavior indicating the existence of free magnetic moments in the Zn doped system. We interpret these results within the RVB picture. 
Th.A. Maier, M. Jarrell