Quantummetamaterials in the microwave and optical ranges

*Correspondence: [email protected] 1Department of Physics, Loughborough University, Loughborough, LE11 3TU, United Kingdom 2Theoretical Physics and Quantum Technologies Department, Moscow Institute for Steel and Alloys, Moscow, 119049, Russia Full list of author information is available at the end of the article Abstract Quantummetamaterials generalize the concept of metamaterials (artificial optical media) to the case when their optical properties are determined by the interplay of quantum effects in the constituent ‘artificial atoms’ with the electromagnetic field modes in the system. The theoretical investigation of these structures demonstrated that a number of new effects (such as quantum birefringence, strongly nonclassical states of light, etc.) are to be expected, prompting the efforts on their fabrication and experimental investigation. Here we provide a summary of the principal features of quantum metamaterials and review the current state of research in this quickly developing field, which bridges quantum optics, quantum condensed matter theory and quantum information processing.