NONEXPONENTIAL RELAXATION IN FULLY FRUSTRATED MODELS

We study the dynamical properties of the fully frustrated Ising model. Due to the absence of disorder the model, contrary to spin glass, doe s not exhibit any Griffiths phase, which has been associated to nonexp onential relaxation dynamics. Nevertheless, we find numerically that t he model exhibits; a stretched exponential behavior below a temperatur e T-p corresponding to the percolation transition of the Kasteleyn-For tuin clusters. We have also found that the critical behavior of these clusters for a fully frustrated q-state spin model at the percolation threshold is strongly affected by frustration. In fact while in the ab sence of frustration the q=1 limit gives random percolation. in the pr esence of frustration the critical behavior is in the same universalit y class of the ferromagnetic q=1/2-state Potts model.