Nonequilibrium Dynamic Phase Transition in the Ferromagnetic Potts Model

The nonequilibrium dynamic phase transition arises in various magnetic systems such as ferromagnetic Ising model when system is driven by both an external field and temperature simultaneously. In this paper, the nonequilibrium dynamic phase transition in the q-state Potts model in the presence of a time dependent oscillating magnetic field on a simple cubic lattice is investigated by mean field theory and time dependent Ginzburug-Landau equation. For the case of q = 2, with decrease of the temperature the system undergoes a dynamically ordered phase transition, which is characterized by the period averaged magnetization Q, from a dynamically disordered state Q = 0 to the dynamically ordered state Q not equal 0. On the other hand, for the case of q = 3 the system has indicated more complicated behavior than that of q = 2. We investigated those characteristic features of the dynamical phase state from the behavior of the dynamic magnetization and the Liapunov exponent.