Dissertation Defense: Non-Hermitian and Topological Effects in a Nonlinear Resonator

Date: 2023/05/18 - 2023/05/18

Dissertation Title: Non-Hermitian and Topological Effects in a Nonlinear Resonator

Speaker: Yao Chen, Ph.D. candidate at UM-SJTU Joint Institute

Time: May 18th from 8:30 a.m., 2023 (Beijing Time)

Location: Room 414A, Longbin Building

Abstract

Exceptional points (EPs), universally present in non-Hermitian systems, often reveal some critical behaviors like topological encircling chirality and ultrahigh enhanced sensing. However, most of the experimental realizations of EPs have been limited to the linear regime. Here we experimentally observe two distinct EPs with opposite hermiticities and demonstrate a parity-time (PT) phase transition with exotic memory effects near the EPs in a nonlinear and non-Hermitian system in an optical microcavity. This scheme completes the studies of non-Hermitian physics in a more general scenario by including nonlinearity and paves the way towards optical memory for all-optical signal processing and quantum information.

Biography

Yao Chen received a B.E. degree in optoelectronic information science and engineering from Huazhong University of Science and Technology, Wuhan, China, in 2018. Since 2018, he has been working toward a Ph.D degree in Nonlinear Nano Photonics Laboratory, Shanghai Jiaotong University, China. His research interests include nonlinear microcavity and optical sensing.