Campus Units

Physics and Astronomy, Mathematics, Ames Laboratory

Document Type

Article

Publication Version

Published Version

Publication Date

6-2007

Journal or Book Title

Physical Review E

Volume

75

Issue

6

First Page

061129-1

Last Page

061129-14

DOI

10.1103/PhysRevE.75.061129

Abstract

The quadratic contact process is formulated as an adsorption-desorption model on a two-dimensional square lattice. It involves random adsorption at empty sites and correlated desorption requiring diagonally adjacent pairs of empty neighbors. We assess the model behavior utilizing kinetic Monte Carlo simulations. One finds generic two-phase coexistence between a low-coverage active steady state and a completely covered or "poisoned" absorbing steady state; i.e., both states are stable over a finite range of adsorption rates or "pressures." This behavior is in marked contrast to that for equilibrium phase separation. For spatially homogeneous systems, we provide a comprehensive characterization of the kinetics of relaxation to the steady states. We analyze rapid poisoning for higher pressures above an effective spinodal point terminating a metastable active state, nucleation-mediated poisoning in the metastable region, the dynamics of poisoned droplets within the two-phase coexistence region, and behavior reminiscent of bootstrap percolation dynamics for lower pressures. For spatially inhomogeneous systems, we analyze the propagation of planar interfaces between active and absorbing states, fully characterizing an orientation dependence which underlies the generic two-phase coexistence.

Comments

This article is from Physical Review E 75 (2007): 061129, doi: 10.1103/PhysRevE.75.061129. Posted with permission.

Copyright Owner

American Physical Society

Language

en

File Format

application/pdf

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