Phase instability and coarsening in two dimensions.
Instabilities and pattern formation is the rule in nonequilibrium systems. Selection of a persistent length scale or coarsening (increase in the length scale with time) are the two major alternatives. When and under which conditions one dynamics prevails over the other is a long-standing problem, particularly beyond one dimension. It is shown that the challenge can be defied in two dimensions, using the concept of phase diffusion equation. We find that coarsening is related to the lambda dependence of a suitable phase diffusion coefficient, D11(lambda) , depending on lattice symmetry and conservation laws. These results are exemplified analytically on prototypical nonlinear equations.
Misbah
Chaouqi
C
Laboratoire de Spectrométrie Physique, UMR, 140 Avenue de la Physique, Université Joseph Fourier Grenoble and CNRS, 38402 Saint Martin d'Heres, France. chaouqi.misbah@ujf-grenoble.fr
Politi
Paolo
P