Beyond Closed Wave Systems: Non-Hermiticity and Vacuum Fluctuations
报告时间：
2023年1月1日 10:00–11:30
报告嘉宾：
丁鲲 研究员（复旦大学物理学系）
主办单位：
武汉光电国家研究中心
直播通道
蔻享学术直播间
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报告人介绍
丁鲲 青年研究员
复旦大学物理学系
丁鲲，青年研究员，2013年毕业于复旦大学物理学系并获博士学位，师从周磊教授。2013-2018年，他于香港科技大学高等研究院和物理系先后担任博士后和科研助理教授，师从陈子亭教授 (Prof. C. T. Chan); 2019-2020年，在英国帝国理工学院Sir John B. Pendry教授课题组从事博士后研究。2021年1月加入复旦大学物理学系，近年来主要的研究方向为经典波系统的非厄米光物理、光学等离子体激元和涨落物理。
报告简介
The classical electromagnetic wave system has demonstrated itself as an excellent platform to realize novel phenomena that may be challenging to implement in other physical systems experimentally. The bedrock principles are to utilize the macroscopic quantities, which are obtained from the homogenization or mean-field treatment, in the wave equations for optics. However, it usually ignores the non-Hermiticity from the interaction between different (quasi-) particles and averages out their fast variations. Therefore, the presentation will cover two topics: non-Hermitian physics and the Casimir effect. The first part will focus on the wonderland of exceptional points (EPs), ranging from the EP geometry to the consequences of EPs. As the cusp singularity of multiple exceptional arcs (EAs), an exceptional nexus (EX) with a hybrid topological invariant has been realized. Such an EX provides an excellent platform to investigate non-Abelian state braiding and higher-order EAs. Moreover, the occurrence of EPs gives rise to geometry-dependent skin effects. The second part will talk about Casimir-induced instabilities at metallic surfaces. Surface plasmons subjected to a surface distortion split asymmetrically in energy resulting in a net lowering of zero-point energy, a statement generally true for optical excitations. It thus gives rise to the instabilities of metallic surfaces and provides a fundamental length scale limit to planar nanostructures.