Switchable multifunctional terahertz coding metasurface containing Dirac semimetal for wavefront manipulation

Abstract Dirac semimetal (DSM) coding metasurfaces enable switchable beam control in the terahertz (THz) communication field, thereby providing additional options for the regulation of electromagnetic waves. This study proposes a new structure based on a DSM THz coding metasurface. By adjusting the DSM size, a coding metasurface containing eight units is constructed to realize 3-bit coding. Simultaneously, by adjusting the DSM Fermi level ( E F ), the relative phase delay of adjacent units is controlled, resulting in a switchable coding metasurface. Using specific coding arrangements, multi-functions, such as beam deflection, beam splitting, vortex beams, and vortex beams with adjustable deflection angles can be controlled. Furthermore, a reduce radar cross-section (by approximately 13 dB at an operating frequency of 1.05 THz), is achieved. This study provides novel concepts and methods for metamaterials in the fields of communication and radar.