Twin-vortex solitons in nonlocal nonlinear media

TL;DR

This paper discovers a new class of stable, topologically complex soliton states in thermal nonlinear media with rectangular boundaries, revealing unique vortex configurations and stability properties.

Contribution

It introduces a novel class of stationary topological solitons with separated singularities in nonlocal media, challenging previous assumptions about vortex state existence.

Findings

Higher-order vortex states do not exist in standard shapes.

Double-charge vortex states are robust despite asymmetry.

Higher topological charges are unstable.

Abstract

We consider soliton formation in thermal nonlinear media bounded by rectangular cross-sections and uncover a new class of nonlinear stationary topological state. Specifically, we find that stationary higher-order vortex states in standard shapes do not exist, but rather they take the form of multiple, spatially separated single-charge singularities nested in an elliptical beam. Double-charge states are found to be remarkably robust despite their shape asymmetry and the phase-singularity splitting. States with higher topological charges are found to be unstable.