The two-dimensional site-diluted Ising ferromagnet a damage-spreading analysis

The quenched site-diluted Ising ferromagnet on a square lattice, for which each site is occupied or empty with probabilities p and 1 − p, respectively, is studied numerically through damage-spreading procedures. By making use of the Glauber dynamics, the percolation threshold pc is estimated. Within the heat-bath dynamics, the damage-spreading temperatures Td(p) (for several values of p>pc) are computed, indicating a strong correlation with the corresponding critical temperatures Tc(p). A procedure for estimating the fractal dimensions of clusters of damaged sites, at low temperatures, is presented; as p → pc, our estimate is very close to 91/48, which is the fractal dimension of the infinite cluster at p = pc in two-dimensional site percolation. Whenever possible to compare, our results are in good agreement with the best estimates available from other techniques, in spite of a modest computational effort.