Quantum Metamaterials with Magnetic Response at Optical Frequencies.

We propose novel quantum antennas and metamaterials with a strong magnetic response at optical frequencies. Our design is based on the arrangement of natural quantum emitters with only electric dipole transition moments at distances smaller than a wavelength of light but much larger than their physical size. In particular, we show that an atomic dimer can serve as a magnetic antenna at its antisymmetric mode to enhance the decay rate of a magnetic transition in its vicinity by several orders of magnitude. Furthermore, we study metasurfaces composed of atomic bilayers with and without cavities and show that they can fully reflect the electric and magnetic fields of light, thus, forming nearly perfect electric or magnetic mirrors. The proposed metamaterials will embody the intrinsic quantum functionalities of natural emitters such as atoms, ions, color center, or molecules and can be fabricated with available state-of-the-art technologies, promising several applications both in classical optics and quantum engineering.