Site order parameters for +/- J Ising lattices

Two different site order parameters are considered to characterize the part ial spin-glass behavior of +/-J square Ising lattices. On the one hand, q p roposed by Edwards and Anderson two decades ago; on the other p, a more dra stic parameter introduced recently. Site order parameters depend very stron gly on the way ergodic separation is performed. Here, we deal with three di fferent ways of doing so, thus allowing to find the most representative par ameter with the appropriate ergodic separation, to have a more sensitive me thod to characterize the spin-glass phase. implications of clustering in th e configuration space on order parameters are also discussed. (C) 2000 Else vier Science B.V. All rights reserved.