Phase transitions in nonequilibrium d-dimensional models with q absorbing states.
A nonequilibrium Potts-like model with q absorbing states is studied using Monte Carlo simulations. In two dimensions and q=3 the model exhibits a discontinuous transition. For the three-dimensional case and q=2 the model exhibits a continuous transition with beta=1 (mean field). Simulations are inconclusive, however, in the two-dimensional case for q=2. We suggest that in this case the model is close to or at the crossing point of lines separating three different types of phase transitions. The proposed phase diagram in the (q,d) plane is very similar to that of the equilibrium Potts model. In addition, our simulations confirm the field-theory prediction that in two dimensions a branching-annihilating random walk model without parity conservation belongs to the directed percolation universality class.
Lipowski
Adam
A
Department of Physics, University of Genève, CH 1211 Genève 4, Switzerland.
Droz
Michel
M