Tunable Electromagnetically Induced Transparency in Asymmetric Graphene-Based Metamaterial at Terahertz Region

We theoretically investigate the active control of electromagnetic induced transparency (EIT) in a terahertz graphene-based metamaterial, whose unit cell structure is composed two perpendicularly connected graphene cut-wires. The theoretical investigations and field distributions reveal that the EIT window arises from the destructive interference caused by asymmetric coupling between two cut-wire structures. Moreover, the strength and frequency of the EIT peak, the associated group delay and delay bandwidth product can be actively controlled. Therefore, the work presents a novel modulation strategy for controlling EIT behavior and exhibits potential applications for switching, modulation, and slow-light devices.