We investigate the behavior of nonequilibrium phase transitions under the influence of disorder that locally breaks the symmetry between two symmetrical macroscopic absorbing states. In equilibrium systems such "random-field" disorder destroys the phase transition in low dimensions by preventing spontaneous symmetry breaking. In contrast, we show here that random-field disorder fails to destroy the nonequilibrium phase transition of the one- and two-dimensional generalized contact process. Instead, it modifies the dynamics in the symmetry-broken phase. Specifically, the dynamics in the one-dimensional case is described by a Sinai walk of the domain walls between two different absorbing states. In the two-dimensional case, we map the dynamics onto that of the well studied low-temperature random-field Ising model. We also study the critical behavior of the nonequilibrium phase transition and characterize its universality class in one dimension. We support our results by large-scale Monte Carlo simulations, and we discuss the applicability of our theory to other systems.
H. Barghathi and T. Vojta, "Random Field Disorder at an Absorbing State Transition in One and Two Dimensions," Physical Review E - Statistical, Nonlinear, and Soft Matter Physics, vol. 93, no. 2, American Physical Society (APS), Feb 2016.
The definitive version is available at https://doi.org/10.1103/PhysRevE.93.022120
Center for High Performance Computing Research
Keywords and Phrases
Domain Walls; Intelligent Systems; Ising Model; Monte Carlo Methods; Temperature; Absorbing-State Transitions; Critical Behavior; Equilibrium Systems; Low Temperatures; Nonequilibrium Phase Transitions; Random Field Ising Models; Spontaneous Symmetry Breaking; Universality Class; Dynamics
International Standard Serial Number (ISSN)
Article - Journal
© 2016 American Physical Society (APS), All rights reserved.
01 Feb 2016