Monte Carlo lattice-gas simulations of stable and unstable interfaces

We describe numerical investigations of the dynamics of interfaces in two dimensions, using a Monte Carlo algorithm that combines elements of both the microcanonical and the canonical methods. We employ a lattice-gas Hamiltonian which corresponds to a system with a first-order phase transition, so that we can study interfaces between distinct thermodynamic phases. Results include the first numerical observation of roughening dynamics for Hohenberg and Halperin’s model C of critical dynamics, and the first numerical observation of the Mullins-Sekerka instability which results from the presence of a thermal gradient