| Time：1131112 (Tues.) 15:00~17:00 Speaker：林振冬Jhen-Dong Lin Postdoctoral Research Fellow, Center for Quantum Frontiers of Research & Technology (QFort) Title：Non-Markovian Quantum Exceptional Points Abstract： Exceptional points (EPs) are spectral singularities known for inducing a variety of exotic features and applications in non-Hermitian systems. Recently, open quantum systems have garnered attention as EP testbeds due to their inherent non-Hermitian characteristics. However, most existing studies have focused on the Markovian limit, leaving a gap in our understanding of EPs within the non-Markovian regime. In this talk, I will present our recent advancements in establishing a general framework for non-Markovian EPs. This framework is based on pseudomode mapping and the hierarchical equations of motion. Our approach enables conventional spectral analysis for EP identification, establishing direct connections between EPs and their dynamic manifestations in open systems. Notably, we uncover purely non-Markovian EPs, which remain unobservable in the Markovian limit. Remarkably, the EP coincides with the transition from Markovian to non-Markovian dynamics, and the EP condition can be fine-tuned by adjusting the environmental spectral properties. Furthermore, we demonstrate that structured environments can elevate the order of EPs, thereby enhancing the sensitivity of the system. These findings provide a theoretical foundation and open new avenues for non-Markovian reservoir engineering and non-Hermitian physics. Place：F104, Gongguan Campus, NTNU |
