Microwave Transmission Through A Superconducting Metamaterial

An important new prediction for negative index of refraction materials is that of evanescent wave amplification under the ideal condition of n = -1 + $i$ 0 precisely, in the absence of retardation effects. This property will permit, in principle, image reconstruction with arbitrary precision and detail. Current metamaterial designs suffer from high losses due to metallic and dielectric dissipation of the elements. We employ a metamaterial design with superconducting and low-loss dielectric materials to reduce these losses. In addition, we observe qualitatively new behavior of the metamaterial arising from the unique electrodynamic properties of superconductors. We present data on a wire medium, a loop medium, and a combination of the two. Novel features not seen at room temperature are manifest in the superconducting state. For example, we can examine the properties of a single loop as a function of temperature and measure its tunability due to the kinetic inductance variation. The prospect of observing evanescent wave amplification is discussed. This work is supported by the National Science Foundation through grant NSF/ECS-0322844.