Triangular anisotropies in driven diffusive systems: reconciliation of up and down.

Deterministic coarse-grained descriptions of driven diffusive systems (DDS) have been hampered by apparent inconsistencies with the kinetic Ising models of DDS. In the evolution towards the driven steady-state, "triangular" anisotropies in the two systems point in opposite directions with respect to the drive field. We show that this is nonuniversal behavior in the sense that the triangular anisotropy "flips" with local modifications of the Ising interactions. The sign and magnitude of the triangular anisotropy also vary with temperature. We have also flipped the anisotropy of coarse-grained models, though not yet at the latest stages of evolution. Our results illustrate the comparison of deterministic coarse-grained and stochastic Ising DDS studies to identify universal phenomena in driven systems. Coarse-grained systems are particularly attractive in terms of analysis and computational efficiency.