Tunability of superconducting metamaterials

TitleTunability of superconducting metamaterials
Publication TypeJournal Article
Year of Publication2007
AuthorsRicci MC, Xu H, Prozorov R, Zhuravel AP, Ustinov AV, Anlage SM
Journal TitleIeee Transactions on Applied Superconductivity
Date PublishedJun
Type of ArticleProceedings Paper
ISBN Number1051-8223
Accession NumberISI:000248442200200
Keywordsfrequencies, HANDED TRANSMISSION-LINES, left-handed, metamaterial, negative refraction, RESONATORS, superconductivity

Metamaterials are artificial structures with unique electromagnetic properties, such as relative dielectric permittivity and magnetic permeability with values less than 1, or even negative. Because these properties are so sensitive to loss, we have developed metamaterials comprised of superconducting waveguides, wires, and split-ring resonators. An important requirement for applications of these metamaterials is the ability to tune the frequency at which the unique electromagnetic response occurs. In this paper we present three methods (unique to superconductors) to accomplish this tuning: temperature, dc magnetic field, and rf magnetic field. Data are shown for dc and rf magnetic field tuning of a single Nb split-ring resonator (SRR). It was found that the dc field tuning was hysteretic in the resonant frequency data, while the quality factor, Q, was less hysteretic. The rf power tuning showed no hysteresis, but. did show suppression of the Q at high power. Magneto-optical images reveal inhomogeneous magnetic vortex entry in the dc field tuning, and laser scanning photoresponse images for a YBa2Cu3O7-6 SRR reveals the current distribution in the rings.

Alternate JournalIEEE Trans. Appl. Supercond.