Dynamical and stationary critical behavior of the Ising ferromagnet in a thermal gradient
arXiv:1208.0965 · doi:10.1140/epjb/e2012-30051-1
Abstract
In this paper we present and discuss results of Monte Carlo numerical simulations of the two-dimensional Ising ferromagnet in contact with a heat bath that intrinsically has a thermal gradient. The extremes of the magnet are at temperatures , where is the Onsager critical temperature. In this way one can observe a phase transition between an ordered phase () and a disordered one () by means of a single simulation. By starting the simulations with fully disordered initial configurations with magnetization corresponding to , which are then suddenly annealed to a preset thermal gradient, we study the short-time critical dynamic behavior of the system. Also, by setting a small initial magnetization , we study the critical initial increase of the order parameter. Furthermore, by starting the simulations from fully ordered configurations, which correspond to the ground state at T=0 and are subsequently quenched to a preset gradient, we study the critical relaxation dynamics of the system. Additionally, we perform stationary measurements () that are discussed in terms of the standard finite-size scaling theory. We conclude that our numerical simulation results of the Ising magnet in a thermal gradient, which are rationalized in terms of both dynamic and standard scaling arguments, are fully consistent with well established results obtained under equilibrium conditions.