Metastable two-component solitons near an exceptional point

TL;DR

This paper investigates two-component solitons in a 2D nonlinear waveguide near an exceptional point, revealing stable and metastable propagation regimes influenced by perturbations and spectrum characteristics.

Contribution

It introduces a new analysis of two-component solitons near an exceptional point, deriving envelope equations and demonstrating their stability and metastability in a perturbed waveguide.

Findings

Stable propagation of two-component solitons near the EP.

Metastable solitons persist over long distances.

Derived one-dimensional envelope equations for the components.

Abstract

We consider a two-dimensional nonlinear waveguide with distributed gain and losses. The optical potential describing the system consists of an unperturbed complex potential depending only on one transverse coordinate, i.e., corresponding to a planar waveguide, and a small non-separable perturbation depending on both transverse coordinates. It is assumed that the spectrum of the unperturbed planar waveguide features an exceptional point (EP), while the perturbation drives the system into the unbroken phase. Slightly below the EP, the waveguide sustains two-component envelope solitons. We derive one-dimensional equations for the slowly varying envelopes of the components and show their stable propagation. When both traverse directions are taken into account within the framework of the original model, the obtained two-component bright solitons become metastable and persist over remarkably long propagation distances.