Artificial metamaterials made to date are all periodic in structure. Here we show that by randomizing contour patterns deposited lithographically on circuit board materials, a metamaterial characterized by a constitutive relation with negative constitutive parameters is produced in solid-state form. We clearly demonstrate the phenomenon of negative refraction to show that it is not produced by periodicity. This underlines the importance of using constitutive relations for media characterization in electromagnetic theory and suggests that metamaterials could be realized with composite materials or fabricated with various techniques by using versatile hosting materials.

No abstract

With a metamaterial structure, the phenomenology observed in quantum electromagnetically induced transparency is reproduced. Through the parametric comparison between quantum and classical systems, the physical mechanism of this novel phenomenon has been explained directly in our analysis. In addition, we use another metamaterial structure to mimic a tripod four-level atom and reveal the analog of electromagnetically induced absorption. Our theoretical and experimental studies may not only bring an intuitive understanding of quantum interference in atomic system, but also provide useful guidelines for the design of microwave devices based on metamaterials.

No abstract

No abstract