Nonequilibrium anisotropic phases, nucleation, and critical behavior in a driven Lennard-Jones fluid

摘要

We describe short-time kinetic and steady-state properties of the nonequilibrium phases, namely, solid, liquid, and gas anisotropic phases in a driven Lennard-Jones fluid. This is a computationally convenient two-dimensional model which exhibits a net current and striped structures at low temperature, thus resembling many situations in nature. We here focus on both critical behavior and details of the nucleation process. In spite of the anisotropy of the late-time "spinodal decomposition" process, earlier nucleation seems to proceed by Smoluchowski coagulation and Oswald ripening, which are known to account for nucleation in equilibrium, isotropic lattice systems, and actual fluids. On the other hand, a detailed analysis of the system critical behavior raises some intriguing questions on the role of symmetries; this concerns the computer and field-theoretical modeling of nonequilibrium fluids.