A new look at the nature of linear momentum and the energy of electromagnetic radiation inside negative refractive media

Abstract

More than a century has passed since the concept of wave–particle duality was introduced, where electromagnetic (EM) radiation in a dispersionless free space vacuum is represented by a photon that exhibits both corpuscular and wave natures. Historically, discussions have concentrated on the nature of a photon inside a medium that exhibits dispersion in the refraction property, other than free space. In this paper we call mechanical momentum, wave momentum, and try to match our ‘thought experiments’ with the properties of the photon, or pulse, carrying the EM energy packet. We also try to find the photon's property energy and momentum inside a positive refractive medium. If the medium shows a negative refractive index behavior, then this has profound consequences, and suitable explanations to the classical concept of the corpuscular–wave nature of a photon inside this medium are needed. In this paper, some of the counterintuitive details of the corpuscular–wave nature of a photon inside a negative indexed material are discussed, producing a possible new definition of wave momentum: the concept of ‘reactive energy’ inside a negative indexed material. These definitions and expressions of ‘wave-momentum’ and ‘reactive energy’ pertaining to negative indexed material are new and are discussed and derived by classical means.