New Journal of Physics Toroidal metamaterial

doi:10.1088/1367-2630/9/9/324 Abstract. It is shown that a new type of metamaterial, a 3D-array of toroidal solenoids, displays a significant toroidal response that can be readily measured. This is in sharp contrast to materials that exist in nature, where the toroidal component is weak and hardly measurable. The existence of an optimal configuration, maximizing the interaction with an external electromagnetic field, is demonstrated. In addition, it is found that a characteristic feature of the magnetic toroidal response is its strong dependence on the background dielectric permittivity of the host material, which suggests possible applications. Negative refraction and backward waves exist in a composite toroidal metamaterial, consisting of an array of wires and an array of toroidal solenoids. Toroidal moments were first considered by Zel’dovich in 1957 [1]. They are fundamental electromagnetic excitations that cannot be represented in terms of the standard multipole expansion [2]. The properties of materials that possess toroidal moments and the classification of their interactions with external electromagnetic fields have become a subject of growin