Light pressure on right-handed and left-handed continuous media

The ambiguity of macroscopic description of light pressure on continuous medium originates from the uncertainty of dividing the energy-momentum tensor of electromagnetically excited matter into material and field parts or, equivalently, the total acting force into pressure and deformation terms. We show that from the continuum of formally correct formulations, one can adopt the appropriate form of the macroscopic field stress tensor that allows unified description of pressure during elementary light-matter interactions in right-handed and lefthanded frequency dispersive media. The proposed expressions for the pressure force are simple, convenient and compatible with the polariton momentum hk. The corresponding electromagnetic momentum density generalizes Rytov's definition.