Dynamics of Nucleation in the Ising Model

TL;DR

This paper investigates the nucleation process in a 3D Ising model near the critical temperature, revealing the complex structure of critical nuclei and the importance of multiple variables in the transition state ensemble.

Contribution

It provides new insights into the nucleation pathways and the structure of critical nuclei using transition path sampling and analysis of the transition state ensemble.

Findings

Critical nuclei are rough and anisotropic.

Additional variables beyond size and surface area influence nucleation.

Transmission coefficient along cluster size is approximately 0.35.

Abstract

Reactive pathways to nucleation in a three-dimensional Ising model at 60% of the critical temperature are studied using transition path sampling of single spin flip Monte Carlo dynamics. Analysis of the transition state ensemble (TSE) indicates that the critical nuclei are rough and anisotropic. The TSE, projected onto the free energy surface characterized by cluster size, N, and surface area, S, indicates the significance of other variables in addition to these two traditional reaction coordinates for nucleation. The transmission coefficient along N is ~ 0.35, and this reduction of the transmission coefficient from unity is explained in terms of the stochastic nature of the dynamic model.