Wave polarization and left-handed materials in metallic magnetic composites

We theoretically investigate the existence of left-handed materials in metallic magnetic composites. We find that the composites behave as left-handed materials only when electromagnetic waves are right-hand circularly polarized under longitudinal magnetization or linearly polarized under transverse magnetization. The frequency range in which the metallic magnetic composites behave as left-handed materials depends on the wave polarization and characteristic parameters of the composites. Electric and magnetic dampings of the composites bring a reduction of the frequency band. Large damping may even destroy the existence of left-handed materials in metallic magnetic composites.