Dynamic phase transition, universality, and finite-size scaling in the two-dimensional kinetic Ising model in an oscillating field - art. no. 016120

We study the two-dimensional kinetic Ising model below its equilibrium crit ical temperature, subject to a square-wave oscillating external field. We f ocus on the multidroplet regime, where the metastable phase decays through nucleation and growth of many droplets of the stable phase. At a critical f requency, the system undergoes a genuine nonequilibrium phase transition, i n which the symmetry-broken phase corresponds to an asymmetric stationary l imit cycle for the time-dependent magnetization. We investigate the univers al aspects of this dynamic phase transition at various temperatures and fie ld amplitudes via large-scale Monte Carlo simulations, employing finite-siz e scaling techniques adopted from equilibrium critical phenomena. The criti cal exponents. the fixed-point value of the fourth-order cumulant, and the critical order-parameter distribution all are consistent with the universal ity class of the two-dimensional equilibrium Ising model. We also study the cross-over from the multidroplet regime to the strong-field regime, where the transition disappears.