Cloaking, scattering and coherence properties of epsilon-near-zero materials in transformation optics

This paper shows that epsilon-near-zero (ENZ) / mu-near-zero material can be obtained by using the transformation optics (TO) approach. It shows that when a line is stretched to a cylinder the z component of permittivity and permeability is zero, while the rho and phi components are equal to one. Hence in the presence of a TE mode wave, the cylinder is equivalent to an isotropic ENZ column. We further show that some additional spatial mapping can be applied to eliminate or mimic the scattering of the ENZ cylinder. To verify our proposal, a rigorous analysis based on Maxwell's equations and numerical simulations based on the finite element method are provided. Finally, cloaking and coherence enhancement are taken as examples to demonstrate potential applications of the ENZ material from the viewpoint of TO.