Electrically controllable fishnet metamaterial based on nematic liquid crystal.

A variable index metamaterial is demonstrated by embedding nematic liquid crystal inside fishnet layers' void at microwave frequencies. With an external electric field, the left handed passband can be reversibly shifted from 9.14 to 8.80 GHz, whereas the upper right handed passband is nearly unchanged. It is shown that during LC molecular reorientation, magnetic resonance is shifted to a lower frequency because of the permittivity increase between fishnet layers, leading to an effective index change of 1.1 within negative index regime.