报告题目（Title）：Parity-time symmetry along with nonlocal optical solitons and their active controls in a Rydberg atomic gas
报 告 人（Speaker）：杭超 教授 (华东师范大学)
报告时间（Time）：2019年6月13日 （周四）13:00
报告地点（Place）：校本部G403
邀请人（inviter）：张永平
报告摘要（Abstract）：
In this report, I will introduce a scheme to realize parity-time (PT) symmetry and nonlocal optical solitons in a cold Rydberg atomic system with electromagnetically induced transparency. I will show that a two-dimensional (2D) periodic optical potential with PT symmetry can be obtained for the propagation of probe laser field by using an incoherent population pumping between two low-lying levels and spatial modulations of control and assistant laser fields. I will also show that, based on the giant nonlocal Kerr nonlinearity originated from the strong, long-range atom-atom interaction, the system supports 2D nonlocal gap solitons with very low light intensity. In particular, the degree of the nonlocality of the Kerr nonlinearity, which can be actively tuned in our system, can be used to manipulate the phase transition of the PT symmetry and the behavior of the nonlocal optical solitons. Our study opens a route for developing non-Hermitian nonlinear optics, especially for realizing and controlling high-dimensional weak-light optical solitons through adjustable PT symmetry and giant nonlocal optical nonlinearity.
