Kinetics of domain growth in systems with local barriers - art. no. 046115

We study domain growth in spin-1 lattice models having nonconserved spin-fl ip kinetics with local barriers. Our primary motivation is to model the rel axational behavior of physical systems in which molecular motion is impeded by local kinetic barriers. The kinetic constraint is such that a spin from an up (down) state can-flip to a down (up) state only vis. the zero state, which has a higher energy. We examine how the usual curvature-driven domai n growth is affected by these local barriers, and whether the single-spin b arriers have a collective effect. This paper presents comprehensive numeric al results for phase ordering dynamics in this model using Monte Carlo simu lations. We demonstrate dynamical scaling for domain-size distribution func tions and spatial correlation functions. We also present results for the ti me dependence of characteristic length scales and autocorrelation functions . The length-scale behavior is interpreted in terms of the random walk of s teps on domain boundaries. Furthermore, we present a simple stochastic mode l to derive an analytic expression for the autocorrelation function, which exhibits a stretched-exponential behavior over an extended regime-in agreem ent with our numerical simulations.