Analogue of electromagnetically induced transparency by doubly degenerate modes in a U-shaped metamaterial

Analogues of electromagnetically induced transparency (EIT) in metamaterials were usually based on complex structures, either by different resonators or by an introduction of symmetry-broken geometry. In this work, we propose a symmetric U-shaped structure to demonstrate an EIT-like transmission peak that is tunable with the rotation angle of the resonators. It is demonstrated that the doubly degenerate modes with different quality factors, sharing a same U-shaped resonator, is responsible for the EIT-like spectrum due to the destructive interference between them.