报告人题目：A loop theorem for the input-output problems in cavity

报告人：  袁怀洋  博士（南方科技大学）

报告时间：2020 年 01 月 06 日（周一）10：00 -- 11：00

报告地点：北洋园校区32教218室

报告摘要：

The input-output formalism is the basis to study the response of an optical cavity to the external stimulations. The existing theory can usually handle cavity with only one single internal mode. However, there is growing interests in more complex systems, especially the hybrid cavity-matter systems, where the cavity itself contains more than one internal mode. Here we propose a universal loop theory to study the reflection and transmission spectrum of such multi-mode cavity, featuring the interplay of internal loops coupling the internal cavity modes and the external loops connecting the internal modes with the external fields. This loop theory gives a unified picture to interpret the experimental observations on a hybrid magnet-light system, including the asymmetric Fano resonance, Purcell effect, and the repulsive or attractive level crossings. Furthermore, we predict the centrosymmetry breaking of the transmission spectrum when multi-mode inside a cavity are driven. These rich findings highlight the universal applicability of the loop theory in both Hermitian and non-Hermitian systems.

报告人简介：袁怀洋博士， 2010年获得武汉大学物理系学士学位，2015年获得香港科技大学物理系博士学位。2017年至今为南方科技大学物理系研究助理教授。主要从事自旋电子学的理论及其与量子信息的交叉研究，研究兴趣包括纳米尺度磁结构（磁畴、磁畴壁、斯格明子等）的动力学行为，腔自旋电子学，以及磁振子之间的纠缠特性等。