Stable vortex solitons in a ring-shaped partially-PT-symmetric potential

Area of Science:

• Nonlinear optics
• Mathematical physics
• Soliton theory

Background:

• Parity-time (PT) and partially-parity-time (pPT) symmetric systems are crucial in nonlinear physics.
• Previous research focused on nonlinear modes within the symmetry-breaking point of such systems.
• The stability of vortex solitons in these configurations remained an open question.

Purpose of the Study:

• To investigate the existence and stability of vortex solitons in a ring-shaped pPT potential.
• To explore the behavior of these solitons across different topological charges and power levels.
• To present the first instance of stable solitons in a symmetry-breaking system.

Main Methods:

• Theoretical analysis of vortex soliton dynamics in a pPT configuration.
• Numerical simulations to confirm existence and stability.
• Investigation of soliton excitation and power-dependent behavior.

Main Results:

• Stable vortex solitons with varying topological charges were found in the pPT system.
• These stable solitons exist even when the system is beyond the symmetry-breaking point.
• Higher-charged unstable vortices were observed to degenerate into stable lower-charged ones at higher power.
• Robust nonlinear vortices were easily excited using Gaussian beams.

Conclusions:

• The proposed pPT potential supports stable vortex solitons, a significant departure from previous findings.
• This work provides the first experimental evidence of stable solitons in a symmetry-breaking system.
• The findings open new avenues for controlling and utilizing nonlinear light structures.