Metamaterial analog of quantum interference: From electromagnetically induced transparency to absorption

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.