题目：Manipulating Classical WavesUsing Topological Properties
Thestudy on manipulating classical waves can date back to thousands of years ago,while the modern evolution in this classical field was propelled by theinvention of photonic and phononic crystals around three decades ago. Morerecently, people started to classify the band structures of these man-madecrystals in terms of band topology which then led to the newly emerging fieldof topological photonics and phononics. This talk consists of two main parts.In the first part, I will talk about the correspondence between Zak phases andthe surface impedance in one dimensional photonic/phononic crystals withinversion symmetry. The extension of this correspondence to two dimensionalsystems is also briefly discussed. In the second part, I will talk about ourtheoretical and experimental realizations of topological Weyl semimetals withphononic and photonic crystals, in both microwave region and optical region. Iwill also discuss the Weyl points in a homogenous medium.
MengXIAO is now a professor in Wuhan University. Before that, he was a postdocworking with Prof. Shanhui Fan in the electrical engineering department ofStanford University. He got his Ph. D. from the Hong Kong University of Scienceand Technology (Supervisor: Prof. C. T. Chan) and bachelor’s degree from WuhanUniversity. Dr. Xiao has worked on topics such as cloaking effect of perfectlens, and Zak phases and topological transition in one-dimensional systems. Nowhe is mainly interested in the geometric and topological phases of classicalwaves, including but not limited to electromagnetic waves, acoustic waves andelastic waves.