Double-flat-top half-vortices and self-bound solitary wave billiards in cubic-quintic media with intermodal attraction

TL;DR

This paper investigates stable half-vortex states in a bimodal cubic-quintic nonlinear medium, revealing unique self-bound solitary wave behaviors and interactions akin to billiard dynamics within flat-top regions.

Contribution

It introduces the concept of stable half-vortices with different topological charges in cubic-quintic media and describes their dynamic behavior as self-bound solitary wave billiards.

Findings

Stable stationary half-vortex states with distinct flat-top regions

Unstable half-vortices split into interacting fragments

Behavior modeled as a self-bound solitary wave billiard

Abstract

We consider a bimodal light field envelope propagating in a bulk medium characterized by competing cubic and quintic nonlinearities. The subfields are coupled by a cross-phase modulation term and experience effective attraction. We find dynamically stable stationary states which have two distinct flat-top regions with different intensities. These solutions represent half-vortices, where the first and second components are essentially different and, in particular, carry different topological charges: zero for one component and nonzero for the other. The typical propagation of an unstable half-vortex leads to the splitting of the central vortex core into several fragments which quasielastically interact with the boundary of the flat-top region. This behavior is interpreted as a self-bound solitary wave billiard, where the emerging fragments are the billiard balls and the flat-top region is the dynamically deforming table.