Coupled nonlinear Schroedinger field equations for electromagnetic wave   propagation in nonlinear left-handed materials
  For an isotropic and homogeneous nonlinear left-handed materials, for which the effective medium approximation is valid, Maxwell's equations for electric and magnetic fields lead naturally, within the slowly varying envelope approximation, to a system of coupled nonlinear Schroedinger equations. This system is equivalent to the well-known Manakov model that under certain conditions, is completely integrable and admits bright and dark soliton solutions. It is demonstrated that left- and right-handed (normal) nonlinear mediums may have compound bright and dark soliton solutions, respectively. These results are also supported by numerical calculations. 
N. Lazarides (1 and 2) and G. P. Tsironis (3) ((1) Department of   Materials Science and Technology, University of Crete, He...