Groupe de Physique Statistique

We investigate the critical behavior of the two-dimensional 8-state Potts model with an aperiodic distribution of the exchange interactions between nearest-neighbor rows. The model is studied numerically through intensive Monte Carlo simulations using the Swendsen-Wang cluster algorithm. The transition point is located through duality relations, and the critical behavior is investigated using finite-size scaling techniques at criticality. For strong enough fluctuations of the aperiodic sequence under consideration, a second-order phase transition is found. The exponents β/v and γ/v are obtained at the new fixed point.