Asymmetric Solitons in Parity-time-symmetric Double-hump Scarff-ii Potentials

Symmetric and asymmetric solitons that form in self-focusing optical waveguides with parity-time (PT )-symmetric double-hump Scarff-II potentials are investigated. It is shown that the branch corresponding to asymmetric solitons bifurcates out from the base branch of PT -symmetric solitons with the increasing of the input power. The stability of symmetric and asymmetric stationary solitons is investigated by employing both linear stability analysis and direct numerical simulations. The effects of the soliton power, the separation between the two humps of the potential, the width and the modulation strength of the potential, on the structure of the linear stability eigenvalue spectrum is also studied. The different instability scenarios of PT -symmetric solitons have also been revealed by using direct numerical simulations.