Percolating spin-glass domains in diluted +/- J square lattices

The diluted lattice formed by removing all exchange interactions that frust rate in the ground manifold of a +/-J square Ising lattice is studied. The concentration of antiferromagnetic interactions, called x, is varied in the range [0.1,0.9]. Over 100 000 samples 8 x 8 are solved at zero temperature finding that diluted lattices present unfrustrated domains of preferred si zes and shapes; this is explained by probabilistic analysis. 64% of the dil uted lattices percolate for 0.3 less than or equal to x less than or equal to 0.7 (increasing outside this interval) leading to a possible robust part ial spin-glass behavior. The percolation threshold does not depend on x rem aining close to 0.41. (C) 1999 Elsevier Science B.V. All rights reserved.