Two-dimensional vortex dipole solitons in nonlocal nonlinearity with PT-symmetric Scarff-II potential.

Abstract

We investigate the dynamics and stability of two-dimensional (2D) vortex dipole solitons in nonlocal nonlinearity with PT-symmetric Scarff-II potential. We analyze the solitons with single charge and higher-order charge using analytical and numerical methods. By the variational approach, we can obtain analytical solutions for the model. It is found that the nonlocality degree affects the evolution of the beams. We discover that the vortex dipole solitons will undergo stable deformation rather than maintaining their basic profile when the nonlocality is strong. Moreover, the stability of the vortex dipole solitons depends on the potential depth and there exists a threshold, below which the beams can keep their shapes and propagate stably whether the nonlocality is weak, intermediate, or strong. Numerical simulations are consistent with the analytical results.