Electrically Controllable Asymmetric Split-Loop Terahertz Resonator with Outer Square Loop

This paper proposes an asymmetric split-loop resonator with an outer square loop (ASLR-OSL), which can actively control terahertz wave transmission properties while maintaining a high- Q -factor of the asymmetric split-loop resonator (ASLR). An added outer square loop is designed to play the roles of both a metamaterial and a micro-heater, which can control the temperature through a directly applied bias voltage. A vanadium dioxide (VO 2 ) thin film, which exhibits an insulator-metal phase transition with temperature change, is used to control the transmission properties. The proposed ASLR-OSL shows transmission properties similar to those of the ASLR, and they can be successfully controlled by directly applying bias voltage to the outer square loop. Based on these results, an electrically controllable terahertz high- Q metamaterial could be achieved simply by adding a square loop to the outside of a well-known high- Q metamaterial.