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Full-Text Articles in Physics
Steady States Of A Nonequilibrium Lattice Gas, Edward Lyman, Beate Schmittmann
Steady States Of A Nonequilibrium Lattice Gas, Edward Lyman, Beate Schmittmann
Beate Schmittmann
We present a Monte Carlo study of a lattice gas driven out of equilibrium by a local hopping bias. Sites can be empty or occupied by one of two types of particles, which are distinguished by their response to the hopping bias. All particles interact via excluded volume and a nearest-neighbor attractive force. The main result is a phase diagram with three phases: a homogeneous phase and two distinct ordered phases. Continuous boundaries separate the homogeneous phase from the ordered phases, and a first-order line separates the two ordered phases. The three lines merge in a nonequilibrium bicritical point.
Exact Dynamics Of A Reaction-Diffusion Model With Spatially Alternating Rates, M. Mobilia, Beate Schmittmann, R. K. P. Zia
Exact Dynamics Of A Reaction-Diffusion Model With Spatially Alternating Rates, M. Mobilia, Beate Schmittmann, R. K. P. Zia
Beate Schmittmann
We present the exact solution for the full dynamics of a nonequilibrium spin chain and its dual reaction-diffusion model, for arbitrary initial conditions. The spin chain is driven out of equilibrium by coupling alternating spins to two thermal baths at different temperatures. In the reaction-diffusion model, this translates into spatially alternating rates for particle creation and annihilation, and even negative “temperatures” have a perfectly natural interpretation. Observables of interest include the magnetization, the particle density, and all correlation functions for both models. Two generic types of time dependence are found: if both temperatures are positive, the magnetization, density, and correlation …
Anomalous Nucleation Far From Equilibrium, I. T. Georgiev, Beate Schmittmann, R. K. P. Zia
Anomalous Nucleation Far From Equilibrium, I. T. Georgiev, Beate Schmittmann, R. K. P. Zia
Beate Schmittmann
We present precision Monte Carlo data and analytic arguments for an asymmetric exclusion process, involving two species of particles driven in opposite directions on a 2×L lattice. To resolve a stark discrepancy between earlier simulation data and an analytic conjecture, we argue that the presence of a single macroscopic cluster is an intermediate stage of a complex nucleation process: in smaller systems, this cluster is destabilized while larger systems form multiple clusters. Both limits lead to exponential cluster size distributions, controlled by very different length scales.