Non-Hermitian nonlinear optics in atomic systems

报告摘要：A wide class of non-Hermitian Hamiltonians can possess entirely real eigenvalues when they have parity-time (PT)、anti-PT、and non-PT symmetric potentials. Recently, this family of non-Hermitian systems has attracted considerable attention in diverse areas of physics due to their extraordinary properties, especially in optical systems based on solid-state materials, such as coupled gain–loss waveguides and microcavities. Considering the desired refractive index can be effectively manipulated through atomic coherence, it is important to realize such non-Hermitian optical potentials and further investigate their distinct properties in atomic systems. Moreover, it is feasible to acquire large Kerr optical nonlinearity based on the resonance character between light and at-oms, allowing the research extend to nonlinear regime. In this talk, I shall introduce our recent theoretical investigations on the realizations of (non-) PT symmetry with different schemes and demonstrate their diverse optical properties as well as potential applications. The results may be served as useful building blocks for developing novel photonic devices with active light control at very low power level.
报告人简介：Chao Hang is a professor in State Key Laboratory of Precision Spectroscopy, East China Normal University (ECNU) at Shanghai. He got his PhD degree from ECNU in 2007; was working at Lisbon University as a postdoctoral researcher from 2008 until 2011, and was working at State Key Laboratory of Precision Spectroscopy as an associate professor from 2012 until 2017. His research interests include nonlinear propagation of waves and solitons in optical materials, Bose-Einstein condensates and parity-time (PT) symmetric system in optics.