title: Low-temperature nucleation in a kinetic Ising model under different stochastic dynamics with local energy barriers.
abstract: Using both analytical and simulational methods, we study low-temperature nucleation rates in kinetic Ising lattice-gas models that evolve under two different Arrhenius dynamics that interpose between the Ising states a transition state representing a local energy barrier. The two dynamics are the transition-state approximation [T. Ala-Nissila, J. Kjoll, and S. C. Ying, Phys. Rev. B 46, 846 (1992)] and the one-step dynamic [H. C. Kang and W. H. Weinberg, J. Chem. Phys. 90, 2824 (1989)]. Even though they both obey detailed balance and are here applied to a situation that does not conserve the order parameter, we find significant differences between the nucleation rates observed with the two dynamics, and between them and the standard Glauber dynamic [R. J. Glauber, J. Math. Phys. 4, 294 (1963)], which does not contain transition states. Our results show that great care must be exercised when devising kinetic Monte Carlo transition rates for specific physical or chemical systems.
authors.affiliation: Department of Physics, Universidad Simon Bolivar, Caracas 1080, Venezuela. buendia@usb.ve
authors.forename: Gloria M
authors.initials: GM
authors.lastname: Buendia
authors.forename: Per Arne
authors.initials: PA
authors.lastname: Rikvold
authors.forename: Kyungwha
authors.initials: K
authors.lastname: Park
authors.forename: M A
authors.initials: MA
authors.lastname: Novotny