International Journal of Modern Physics B

Monte Carlo simulations of the short-time critical dynamics are reviewed. The short-time universal scaling behavior of the dynamic Ising model and Potts model are discussed in detail, while extension and application to more complex systems as the XY model, the fully frustrated XY model and other dynamic systems are also presented. The investigation of the universal behavior of the short-time dynamics not only enlarges the fundamental knowledge on critical phenomena but also, more interestingly, provides possible new ways to determine not only the new critical exponents θ and θ₁, but also the traditional dynamic critical exponent z as well as all static critical exponents.

The properties of a two-state chain interacting with a phonon bath is studied in this paper. We discuss the renormalization of the single pseudospin tunneling parameter by phonons' interaction, as well as other pseudospins' correlation. We find that for Ohmic dissipation, the correlation between pseudospins vanishes and the phonons' interaction induces the localization–delocalization transition. For our discussed super-Ohmic dissipation, the phonons' interaction only reduces the tunneling parameter and does not induce phase transition. In this case the pseudospins' correlation has its effect and reduces the tunneling parameter at weak coupling. In addition, some application of our results is also discussed.

We introduce a generalized superposition of two coherent states to investigate interference effects between them and their influences upon nonclassical effects. The role played by the involved parameters on each nonclassical effect is shown, including a proposal for generating this state and its application. The present scheme constitutes an unified approach, including various important states studied in the literature.

We report the results of imposing a physically motivated restriction on the step sizes in a (d + 1)-dimensional discrete solid-on-solid (SOS) model, which we have proposed recently (Phys. Rev.E54, 2670 (1996)) for a d-dimensional interface with bending stiffness and interfacial tension. We clarify some features of this model in the absence of such restrictions. We also draw analogies between the relaxation to thermally roughened equilibrium states of these SOS models and nonequilibrium growth of some kinetically roughened model surfaces.