Fig. 1

(a) Schematic diagram of the proposed anapole metamaterial array for refractive index sensing. The inset is the top-view scanning electron microscope image of the fabricated sample. The scale bar is 500 nm. (b) Schematic depiction for the excited anapole mode, which originates from the destructive interference between electric dipole (blue arrow) and toroidal dipole (red arrow with pink torus and green circulating magnetic field) moments