An exact algorithm for spin correlation functions of the two dimensional   +/-J Ising spin glass in the ground state
  We introduce an exact algorithm for the computation of spin correlation functions for the two dimensional +/-J Ising spin glass in the ground state. Unlike with the transfer matrix method, there is no particular restriction on the shape of the lattice sample, and unlike Monte Carlo based methods it avoids extrapolation from finite temperatures. The computational requirements depend only on the number and distribution of frustrated plaquettes. 
J. Poulter and J.A. Blackman