RESUMO
Realizing vector spatiotemporal solitons that are stable in high dimensions is a long-standing goal in the study of nonlinear optical physics. Here, a scheme is proposed to generate three-dimensional (3D) vector spatiotemporal solitons in a cold atomic system with linear and nonlinear parity-time (PT) potentials by utilizing electromagnetically induced transparency (EIT). We investigate the existence and stability of these vector 3D semilunar solitons (SSs) and vortex solitons (VSs) supported by the linear and nonlinear PT potentials. The results show that these solitons have extremely low generation power and very slow propagation velocity and can stably propagate with constant total energy in this system. The frontal head-on collisions of two vector solitons feature quasi-elastic collisions. The dynamics characteristics of these solitons depend on the linear and nonlinear PT-symmetric potential parameters, in particular, the imaginary part of PT potentials. Our study provides a new route for manipulating high-dimensional nonlinear vector optical signals via the controlled optical linear and nonlinear potentials in cold atomic gases.
RESUMO
We propose a realistic physical scheme to realize linear Gaussian optical potential with parity-time (PT) symmetry and two dimensional (2D) spacial solitons in a coherent atomic gas. It is shown that the PT-symmetric potential can be created through the spatial modulation of the control and relevant atomic parameters. We find that the Gaussian PT potential parameters, the imaginary part and the width and the position, play crucial roles in the occurrence of the PT phase transition. We demonstrate that the system supports stable 2D dipole solitons and vortex solitons, which can be managed via tuning PT potential. Furthermore, the dynamic characteristics of the symmetric scatter and collision of solitons are shown.