In this paper, a parametrically driven discrete nonlinear Schrödinger equation will be considered for defocusing case. Analytical and numerical calculations will be performed to determine the existence and stability of intersite dark discrete solitons admitted by discrete nonlinear Schrödinger equation. It will be shown that a parametric driving can stabilizes intersite discrete dark solitons. Stability windows of all the fundamental solitons will be presented and approximations to the onset of instability will be derived using perturbation theory, with accompanying numerical results.

No abstract

In the present paper, we have investigated the solitonic characteristics of a pulse passing through an interface separating two nonlinear media. The first media is a thin film of gallium nanoparticles which show switching properties under optical excitation and second is a monomode optical fiber. Various properties of three different phases of gallium nanoparticles have been analyzed by using the equivalent particle theory and Maxwell-Garnett effective medium theory.

Depending on their strength, the electron-phonon interactions in systems involving electron moving in deformable lattice of atoms can become very important for the dynamics of such systems and may lead to some very interesting phenomena eg. quasiparicle self trapping. We consider Metallic Carbon Nanotube with an excess electron. We choose 2-dimensional hexagonal lattice to be periodic and to have a large extension in one direction and a small extension in the other direction. We study the Modified Nonlinear Schrodinger Equation in Carbon Nanotube (10,10) where the modified term arises due to interaction between excess electron field and lattice distortion and gives stabilization to the solution. This interaction symbolizes strength of nonlinearity in the system. We solved this equation numerically using cylindrical coordinates and found that solutions depend crucially on electron-phonon interaction coefficient.

In this paper, we consider a parametrically driven discrete nonlinear Schrödinger equation. Analytical and numerical calculations are performed to determine the existence and stability of fundamental bright discrete solitons admitted by discrete nonlinear Schrödinger equation. We show that a parametric driving can destabilizes onsite bright solitons and stabilizes intersite bright discrete solitons. Stability windows of all the fundamental solitons are presented and approximations to the onset of instability are derived using perturbation theory, with accompanying numerical results.