Surface polaritons in a vacuum gap inside mu-negative medium

In this paper, we present the theoretical study of metamaterials with negative magnetic permeability in the frame of phenomenological electrodynamics. The slow surface electromagnetic eigenwaves propagated in the vacuum gap inside mu-negative medium have been studied. Its phase velocities are less than the speed of light in a vacuum. The electric field vector of these modes is directed entirely perpendicular to the propagation direction and parallel with interface plane. The distribution of the electric field amplitude of these modes along the coordinate of the perpendicular interface can be symmetric or antisymmetric. Symmetric modes are forward waves at any vacuum gap width. Antisymmetric modes may be forward or backward waves in dependence on the vacuum gap width. With a sufficiently high value of this gap width the influence of the second boundary disappears and we have two single unrelated interfaces between the media. These surface electromagnetic waves can be additional operating modes of modern devices, both in science and industry.