Zero-index Metamaterials for Classical and Quantum Light

Zero-index metamaterials (photonic materials and artificial media with a near-zero refractive index in different parts of the electromagnetic spectrum) make possible novel forms of light-matter interactions where light behaves in a qualitatively different way. There has been an upsurge of exciting discoveries of exotic wave phenomena in these materials, leveraging the impact of their near-zero refractive index on different optical processes. In recent years, these unconventional phenomena have benefitted several photonic technologies, including nonlinear optics, thermal emitters, reconfigurable optical devices, integrated photonics, and quantum technologies.
Interest in zero-index metamaterials has exploded during the last years, bridging nanophotonics, electrical engineering, material science, nanofabrication, and quantum physics. Linking these communities will be instrumental in pushing forward the development of zero-index metamaterials. This Special Topic will serve to summarize the state of the art and strengthen the connections between researchers working in the field.