Metamaterials and the problem of creating invisible objects. 1. Objects with size less than a wavelength

Metamaterials have undergone intense development in the past decade. These are artificial materials consisting of structural elements whose form and relative position can be specified during fabrication. It has been shown to be possible to adjust the electric and magnetic responses of such materials to the action of electromagnetic radiation within wide limits. This has made it possible not only to create metamaterials with a negative refractive index but also to pose the question of the possibility of creating invisible objects. Intense discussion of the problem of creating invisible objects began in 2005, so that there are by now several dozen papers on this topic. This paper presents the first part of a review of the problem of creating invisible objects, concentrating on objects whose size is less than a wavelength of electromagnetic radiation.