BIC-based breaking symmetry E-type resonator

In recent years, metasurfaces have demonstrated remarkable effects in areas such as beam steering, wavefront manipulation, and mode encoding, showcasing their ability for flexible customization in information transmission and processing. This has garnered significant attention. In our work, we discuss a method under the mechanism of Bound States in the Continuum (BIC), where we effectively control the appearance of Fano resonances in metasurfaces by introducing a symmetry-breaking approach. By breaking the x-axis symmetry of the double-E structure, quasi-BIC phenomena can be achieved in the terahertz band. By calculating the Q-factor values, this structure features a symmetry-protected BIC, and the formation of the quasi-BIC is related to the way this BIC symmetry is broken. This lays the foundation for subsequent multi-channel single-band implementations by simultaneously breaking multiple symmetries.