Rakhmanov, A. L.Yampol’skii, V. A.Fan, JingCapasso, FedericoNori, Franco2014-02-122010Rakhmanov, A. L., V. A. Yampol’skii, J. A. Fan, Federico Capasso, and Franco Nori. 2010. Layered superconductors as negative-refractive-index metamaterials. Physical Review B 81 (7): 10.1103.1098-0121http://nrs.harvard.edu/urn-3:HUL.InstRepos:11693947We analyze the use of layered superconductors as strongly anisotropic metamaterials, which can possess negative-refractive-index in a wide frequency range. Superconductors are of particular interest because they have the potential to support low losses, which is critical for applications such as super-resolution imaging. We show that low-Tc (s-wave) superconductors can be used to construct layered heterostructures with low losses for \(T \ll Tc\). However, the real part of their in-plane effective permittivity is very large, making coupling into the structure difficult. Moreover, even at low temperatures, layered high-Tc superconductors have a large in-plane normal conductivity, producing large losses (due to d-wave symmetry). Therefore, it is difficult to enhance the evanescent modes in either low-Tc or high-Tc superconductorsen-USJournal Article2014-02-1210.1103/PhysRevB.81.075101