Abstract

Keqiang Lyu (KAUST), Changqing Xu(Nanjing Normal University), Yun Lai(Nanjing University) and Guancong Ma(Hong Kong Baptist University) In this presentation, I will provide a brief overview of various homogenization schemes developed for periodic structures. Specifically, I will focus on the multiple-scatterin based effective medium, and elucidate the link between effective properties and local resonances.Next, I will delve into the latest developments in double-zero-index materials, where permittivity and permeability, or mass density and compressibility, can simultaneously become zero. I will highlight the role played by effective medium theory in designing these materials. To demonstrate how to achieve the desired resonances leading to double-zero index, I will showcase several examples, including three-dimensional electromagnetic and acoustic metamaterials, as well as a two-dimensional acoustic metamaterial.