Some aspects of mass-energy equivalence in negative refractive index mediums

In this thesis, the possibility of negative refractive index in plasma and magnetic materials was considered with a new approach. It is shown that simplification of fundamental equations by neglecting losses leads to losing important features about refractive index and therefore, it is expedient to take into consideration imaginary parts of dielectric permittivity and magnetic permeability for an accurate statement of the problem. Also active materials were briefly discussed via new approach. Moreover, the concept of mass-energy equivalence in left handed metamaterials is discussed by following Einstein's box thought experiment. Left handed metamaterials, artificial composite structures that are exhibit unusual properties, especially negative refractive index, in which phase and group velocities are directed oppositely. Equation, E=mc2 , assumes that, in vacuum, the propagation of an electromagnetic radiation from emitter to receiver is accompanied by the transfer of mass. It was hypothesized previously that, if the space between emitter and receiver is medium with a negative refractive index, then radiation transfers the mass not from the emitter to receiver as expected, but rather from the receiver to the emitter due to the opposite directions of phase and group velocities. In this work, it is shown that even though one radiating atom is taken, then the negative mass transferring must be in force. In particular, it means that, if the atom radiates a photon in a medium with negative refractive index, photon transfers the mass not from the atom, but to the atom.