First metamaterial made from superconductors

MIT Technology Review : Many metamaterials are arrays of identical pieces that combine to produce unusual effects, such as negative indexes of refraction. Using superconductors to create metamaterials is desirable because superconductors have less resistance to the passage of light. However, it has been difficult for many reasons, among them the metamaterials’ increased sensitivity to small variances present at temperatures near absolute zero. Pascal Macha of the Karlsruhe Institute of Technology in Germany and his colleagues have overcome many of the difficulties and have created a metamaterial that comprises an array of 20 superconducting quantum circuits embedded in a microwave resonator. They were able to reduce the variance of the circuits so that there was a less than 5% difference in current passing through each circuit. By embedding the circuits in a resonator, the researchers were able to combine them all into a superposition of states so that together they influenced the photons passing through the system. The resulting system showed some unexpected behaviors, but operated as a metamaterial as intended. Further examination of the system may reveal more information about the processes that occur and may open the door for more superconductive metamaterials.