Tuesday, June 12, 2012

1206.1878 (Hatem Barghathi et al.)

Random fields at a nonequilibrium phase transition    [PDF]

Hatem Barghathi, Thomas Vojta
We investigate nonequilibrium phase transitions in the presence of disorder that locally breaks the symmetry between two equivalent macroscopic states. In low-dimensional equilibrium systems, such "random-field" disorder is known to have dramatic effects: It prevents spontaneous symmetry breaking and completely destroys the phase transition. In contrast, we demonstrate that the phase transition of the one-dimensional generalized contact process persists in the presence of random field disorder. The dynamics in the symmetry-broken phase becomes ultraslow and is described by a Sinai walk of the domain walls between two different absorbing states. We discuss the generality and limitations of our theory, and we illustrate our results by means of large-scale Monte-Carlo simulations.
View original: http://arxiv.org/abs/1206.1878

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