SPINODAL DECOMPOSITION OF THE INTERFACE IN NONLINEAR EDWARDS-WILKINSON MODEL

We consider a nonlinear version of the Edwards-Wilkinson interface model for the growth in the presence of a collimated particle flux. We include both surface-tension and surface-diffusion relaxation. In a range of positive small values of the surface tension, the interface develops a state which fulfills standard criteria for spinodal decomposition. This suggests the existence of a phase transition from the ordinary state with the interface perpendicular to the incoming flux to a novel, noise-induced state with the interface spontaneously tilted with respect to the direction of the flux.