Formation of a Dirac Cone and Dynamic Control of its Half-Metallic Properties Using Double-Layer Ring Dipole Arrays

Dirac cone formation and a method for dynamically controlling the band gap using double-layer ring dipole arrays (RDAs) are demonstrated and proposed. The design is mainly based on the composite righthanded-left-handed circuit theorem. It is theoretically and analytically confirmed that the Dirac cone appears at the optimum separation in double-layer RDAs, which are known to have surface-wave modes in the case of a single-layer RDA. It is also found that the band gap can be formed and controlled by decreasing the separation between the two layers. The Dirac cone formation and its dynamic control method on the artificial structure will open the possibility of new transistor applications as an artificial electronic material showing the properties of Dirac half-metals.