“…where ǫ 0 and µ 0 are the permittivity and permeability of vacuum, and ǫ and µ are the relative permittivity and permeability of the specific media. There exist many excellent works on the analysis and applications of finite element method (FEM) for solving the Maxwell's equations in various media, such as in the free space (e.g., papers [3,4,6,7,11,16,17,43], books [12,22,30] and references therein); in general dispersive media (e.g., [2,19,28,34]); in negative index metamaterials [18,38,39]; and in cloaking metamaterials [23][24][25]41]. In recent years, we developed some mathematical models and time-domain FEMs for simulating the invisibility cloaks [23][24][25].…”