Electrically resonant terahertz metamaterials: Theoretical and experimental investigations

We present a class of artificial materials that exhibit a tailored response to the electrical component of electromagnetic radiation. These electric metamaterials are investigated theoretically, computationally, and experimentally using terahertz time-domain spectroscopy. These structures display a resonant response including regions of negative permittivity ${ϵ}_{1}(\ensuremath{\omega})<0$ ranging from $\ensuremath{\sim}500\phantom{\rule{0.3em}{0ex}}\mathrm{GHz}\phantom{\rule{0.3em}{0ex}}\text{to}\phantom{\rule{0.3em}{0ex}}1\phantom{\rule{0.3em}{0ex}}\mathrm{THz}$. Conventional electric media such as distributed wires are difficult to incorporate into metamaterials. In contrast, these localized structures will simplify the construction of future metamaterials, including those with negative index of refraction. As these structures generalize to three dimensions in a straightforward manner, they will significantly enhance the design and fabrication of functional terahertz devices.