Terahertz Full‐Set Multi‐Bit Logic Operations with High‐Dimensional Multiplexed Surface Plasmonic Vortices

ABSTRACT On‐chip photonic logic operations are emerging as a leading candidate for post‐Moore's computing and the terahertz (THz) band is crucial for next‐generation integrated applications. However, THz on‐chip Boolean logic gates still lack a universal paradigm for multifunctionality and reconfigurability, which is largely limited by the inadequate multiplexing and dynamic modulation capabilities. Here, we demonstrate a reconfigurable liquid crystal‐integrated plasmonic metasurface for THz full‐set logic operations. A three‐level coherent synthesis strategy is first established to customize spatiotemporal‐frequency‐spin multiplexed surface plasmonic vortices. Furthermore, a spatio‐temporal encoding mechanism is incorporated to support flexible surface field manipulations and reconstruct multi‐input‐output mappings for complex logic operations. With dual‐pixel and quad‐level encodings, this device delivers active control of vortex mode superposition and suppression, yielding up to 64 distinct nearfield states with a maximum contrast ratio of 20 dB. Surpassing conventional on‐chip logic devices, this platform executes multi‐bit logic operations up to 7‐bit inputs and 2 ¹²⁸ full‐set schemes, which enable parallel encryption and logic computing across multiple on‐chip nodes. This work paves the way for THz ultra‐compact on‐chip photonic links, advancing high‐density data communication and massive data processing applications.