Tunable negative-index photonic crystals using colloidal magnetic fluids*
Geng Tao†, Wang Xin, Wang Yan, Dong Xiang-Mei
       
(a) Band structure, (b) effective permittivity ɛ e and permeability μ e of 2D PC with external magnetic field 200 Oe for TM polarization. In panel (a), the shadow area indicates the band gap.