Spontaneous pattern formation in driven nonlinear lattice
  We demonstrate the spontaneous formation of spatial patterns in   a damped, ac-driven cubic Klein-Gordon   lattice. These   patterns are composed of arrays of intrinsic localized modes   characteristic for nonlinear lattices. We analyze the modulation   instability leading to this spontaneous pattern formation. Our   calculation of the modulational instability is applicable in one   and two-dimensional lattices, however in the analyses of the   emerging patterns we concentrate particularly on the two-dimensional case. 
Andrea Vanossi, K.{\O}. Rasmussen, A.R. Bishop, B.A. Malomed, and V.   Bortolani