Terahertz metasurface based on vanadium dioxide for realizing CNOT logic gate and tunable vortex beams

• A anisotropic VO 2 metasurface was proposed, and the CNOT logical operation and tunable vortex beam were achieved through a simple method. • The phase regulation of the metasurface can be achieved by adjusting the state of VO 2 and the polarization direction of the incident wave. • The metasurface exhibits the outstanding ability of wavefront modulation within the wide frequency range of 0.4–1.2 THz. • Near- and far-field analyses confirm the effectiveness of the generated OAM beams. Independent phase control of circularly polarized light on a single metasurface is highly desirable for terahertz applications. However, most metasurfaces reported suffer from two critical limitations: the lack of dynamic tunability and narrow operational bandwidth. We present a dynamically tunable terahertz metasurface featuring multifunctional optical responses, enabled by the insulating-to-conducting phase transition of vanadium dioxide. This approach facilitates active modulation of optical properties through thermal excitation, allowing for reconfigurable wavefront manipulation in the terahertz regime. By exploiting the Pancharatnam-Berry phase modulation combined with propagating phase engineering, we demonstrate our approach through a two-parameter CNOT logic gate and switchable vortex beams with tunable topological charges across the 0.4–1.2 THz band. Our tunable metasurface devices open up potential applications in various fields, including imaging and communications in the terahertz range.