Dynamical origin of spontaneous symmetry breaking in a field-driven nonequilibrium system

¹ Institut für Festkörperforschung, Forschungszentrum Jülich - 52425 Jülich, Germany
² Zentrum Mathematik, TU München - 85747 Garching bei München, Germany

Received: 22 April 2005
Accepted: 9 June 2005

Abstract

A one-dimensional driven two-species model with parallel sublattice update and open boundaries is considered. Although the microscopic many-body dynamics is symmetric with respect to the two species and interactions are short-ranged, there is a region in parameter space with broken symmetry in the steady state. The sublattice update is deterministic in the bulk and allows for a detailed analysis of the relaxation dynamics, so that symmetry breaking can be shown to be the result of an amplification mechanism of fluctuations. In contrast to previously considered models, this leads to a proof for spontaneous symmetry breaking which is valid throughout the whole region in parameter space with a symmetry-broken steady state.