Cloaking Device for Electromagnetic Surface Waves
A 'cloaking device' renders an object undetectable for electromagnetic radiation so that an outside observer cannot register any scattering or reflection effects from that object. Recent approaches commonly consider electromagnetic waves in three dimensions, i.e. light, as a probe. In this paper we demonstrate how it is possible to hide an object located on a metal surface from interaction with surface plasmon polaritons, a collective excitation of light and free electrons in only two dimensions. Our cloaking device consists of point scatterers distributed on two concentric rings around the object to be cloaked. By computer simulations we determine the physical properties of these point scatterers required to acheive the cloaking effect. As it turns out, the cloaking geometry efficently reduces scattering from the enclosed object to a minimum. We conclude that such point scatterers can be formed by surface defects that seem to be easy to create by the photon scanning tunneling microscope/direct-write lithography technique.
