Polytype kinetics and quenching of spin chains with competing interactionsusing trimer-flip dynamics

We consider the effects of a quench to T = 0 on a spin system with axial ne xt-next nearest neighbour Ising interactions, evolving under a conserved 3- spin flip dynamics. Such a model is motivated by the kinetics of stacking l ayers in polytypes near the 3C-6H transition. We find that the system gener ically gets arrested in interesting metastable states which have inhomogene ously distributed quiescent and active regions. In such arrested states, th e autocorrelation function decays as a stretched exponential similar to exp (-(t/(o)tau)(1/3)). The latter feature can be understood in terms of a mapp ing of the dynamics within active stretches to the well known simple exclus ion process of particles on a line, and bounds can be put on tau(o). (C) 19 99 Elsevier Science B.V. All rights reserved.