Non-equilibrium critical dynamics of the kinetic Baxter model

The non-equilibrium critical dynamics of the Baxter model is studied through Monte Carlo simulations. The single-spin-flip stochastic dynamics is introduced on the basis of the formulation of the model as an Ising-type model on the square lattice with next-nearest-neighbor and four-spin interactions. At several points on the critical line, the dynamic critical exponent z and the critical exponent <(lambda)over bar>(c), which characterizes the non-equilibrium critical relaxation, are estimated for the two order parameters of the model, the magnetization and the polarization. For both order parameters, the estimated <(lambda)over bar>(c) varies systematically along the critical line. On the other hand, the estimated z is almost constant. This suggests that while the exponent z is universal, the exponent <(lambda)over bar>(c) is not.