Extended Group-Theoretical Approach to Metamaterials With Application to THz Graphene Fish-Scale Array

We develop a group-theoretical method for analysis of metamaterials which includes both longitudinal and transversal components of currents in different parts of molecules. In comparison with the existing approach which takes into account only longitudinal components, our method allows one to obtain more information about the properties of metamaterials. As an example of the method application, we suggest and analyze an electromagnetic graphene array for terahertz region. Depending on the parameters of the structure, different types of the absorption resonances can exist in the structure which are discussed from the point of view of symmetry.