Plane waves with negative phase velocity in Faraday chiral mediums

The propagation of plane waves in a Faraday chiral medium was discussed. It was found that conditions for the phase velocity to be directed opposite to the direction of power flow were derived for propagation in an arbitrary directions. The negative phase-velocity conditions were analyzed numerically using a representative Faraday chiral medium. Analysis shows that the phase velocity was directed opposite to power flow when the gyrotropic parameters of the ferrite component medium was sufficiently large compared to the corresponding nongyrotropic permeability parameters.