Dynamics of multidimensional fundamental and vortex solitons in random media

TL;DR

This paper develops a new analytical method to study the behavior of fundamental and vortex solitons in multidimensional random media, revealing that fluctuations cause solitons to spread without collapsing.

Contribution

A novel technique for calculating higher-order moments in stochastic nonlinear Schrödinger equations without perturbation or closure assumptions.

Findings

Solitons spread out under random fluctuations, preventing collapse.

Analytical expressions for mean intensity, variance, and coherence of solitons.

The method applies to multidimensional systems with spatially and temporally varying randomness.

Abstract

We study the dynamics of fundamental and vortex solitons in the framework of the nonlinear Schr\"{o}dinger equation with the spatial dimension $D\geqslant 2$ with a multiplicative random term depending on the time and space coordinates. To this end, we develop a new technique for calculating the even moments of the $N$th order. The proposed formalism does not use closure procedures for the nonlinear term, as well as the smallness of the random term and the use of perturbation theory. The essential point is the quadratic form of the autocorrelation function of the random field and the special stochastic change of variables. Using variational analysis to determine the field of structures in the deterministic case, we analytically calculate a number of statistical characteristics describing the dynamics of fundamental and vortex solitons in random medium, such as the mean intensities, the variance of the intensity, the centroid and spread of the structures, the spatial mutual coherence function etc. In particular, we show that, under the irreversible action of fluctuations, the solitons spread out, i.e., no collapse occurs.