The electron states in axially symmetric quantum wires are computed by means of the effective mass Schrodinger equation, which is written in cylindrical coordinates \phi, \rho, and z. We show that a direct discretization of the Schrodinger equation by central finite differences leads to a nonsymmetricHamiltonian matrix. Because diagonalization of such matrices is more complex it is advantageous...

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Introduction. We are going to present here some brief survey of the results of Theory of Solitons (see [1–3]) from the viewpoint of periodic theory including some new results in the theory of 2-dimensional periodic Schrodinger Operators. A remarkable connection of some very special but highly nontrivial nonlinear (especially one-dimensional) systems with spectral properties of one-dimensional l...

We consider the nonlinear Schrodinger equation with the nonlinearity management which describes Bose-Einstein condensates under Feshbach resonance. By using an averaging theory, we derive the Hamiltonian averaged equation and compare it with other averaging methods developed for this problem. The averaged equation is used for analytical approximations of nonlinearity-managed solitons.

Abstract. We consider a nonlinear Schrodinger equation (NLS) with dissipation and forcing in critical dimension. Without both linear and nonlinear dissipation NLS results in a flnite-time singularity (collapse) for any initial conditions. Dissipation ensures collapse regularization. If dissipation is small then multiple near-singular collapses are randomly distributed in space and time forming ...