Solitons in the nonlinear Schrödinger equation with two power-law nonlinear terms modulated in time and space

A nonlinear Schrödinger equation that includes two terms with power-law nonlinearity and external potential modulated both on time and on the spatial coordinates is considered. The model appears in various branches of contemporary physics, especially in the case of lower values of the nonlinearity power. A significant generalization of the similarity transformations approach to construct explicit localized solutions for the model with arbitrary power-law nonlinearities is introduced. We obtain the exact analytical bright and kink soliton solutions of the governing equation for different nonlinearities and potentials that are of particular interest in applications to Bose-Einstein condensates and nonlinear optics. Necessary conditions on the physical parameters for propagating envelope formation are presented. The obtained results can be straightforwardly applied to a large variety of nonlinear Schrödinger models and hence would be of value to understand nonlinear phenomena in a diversity of nonlinear media.

Figure 1

Intensity ${\left|u(x,t)\right|}^2$ distribution of the bright soliton given by Eq. (30) with the parameter values $E=-1,G_1=-2,G_2=0.25$, and $V_0=3$ for potential and nonlinearities given by Eq. (29).

Figure 2

Intensity ${\left|u(x,t)\right|}^2$ distribution of the kink soliton given by Eq. (31) with the parameter values $G_1=-0.6,G_2=0.05$, and $V_0=1.5$ for potential and nonlinearities given by Eq. (29) .

Figure 3

Intensity ${\left|u(x,t)\right|}^2$ distribution of the bright soliton given by Eq. (37) with the parameter values $E=-1,G_1=-2,G_2=0.25,a=0.5$, and $b=-0.05$ for potential and nonlinearities given by Eqs. (34, 35, 36).

Figure 4

Intensity ${\left|u(x,t)\right|}^2$ distribution of the kink soliton given by Eq. (38) with the parameter values $G_1=-0.6,G_2=0.05,a=0.5$, and $b=-0.1$ for potential and nonlinearities given by Eqs. (34, 35, 36).

Figure 5

Intensity ${\left|u(x,t)\right|}^2$ distribution of the bright soliton given by Eq. (50) with the parameter values $E=-1,G_1=-2,G_2=0.25$, and $V_0=0.2$ for potential and nonlinearities given by Eqs. (47, 48, 49).

Figure 6

Intensity ${\left|u(x,t)\right|}^2$ distribution of the kink soliton given by Eq. (51) with the parameter values $G_1=-0.6,G_2=0.05$, and $V_0=0.2$ for potential and nonlinearities given by Eqs. (47, 48, 49).