A d.c. magnetic metamaterial

Abstract

Electromagnetic metamaterials^1,2,3 are a class of materials that have been artificially structured on a subwavelength scale. They are currently the focus of a great deal of interest because they allow access to previously unrealizable properties such as a negative refractive index⁴. Most metamaterial designs have so far been based on resonant elements, such as split rings⁵, and research has concentrated on microwave frequencies and above. Here, we present the first experimental realization of a non-resonant metamaterial designed to operate at zero frequency. Our samples are based on a recently proposed template⁶ for an anisotropic magnetic metamaterial consisting of an array of superconducting plates. Magnetometry experiments show a strong, adjustable diamagnetic response when a field is applied perpendicular to the plates. We have calculated the corresponding effective permeability, which agrees well with theoretical predictions. Applications for this metamaterial may include non-intrusive screening of weak d.c. magnetic fields.