A Simple Model for the Checkerboard Pattern of Modulated Hole Densities   in Underdoped Cuprates
  A simple model is proposed as a possible explanation for the checkerboard pattern of modulations in the hole density observed in recent tunneling experiments on underdoped cuprates. Two assumptions are made; first, an enhanced hole density near the acceptor dopants and secondly short range correlations in the positions of these dopants caused by their electrostatic and anisotropic elastic interactions. Together these can lead to a structure factor in qualitative agreement with experiment. 
T. M. Rice and Hirokazu Tsunetsugu