Switchable polarization manipulation, optical logical gates and conveyor belt based on U-shaped $\ce{VO2}$ nanoholes

Based on U-shaped plasmonic nanoholes in an $\ce{Au-VO2-Au}$ film, we propose to achieve several switchable functions at the telecom wavelength by transition from the $\ce{VO2}$ semiconductive state to the metallic state. The first is the polarization manipulation of four different polarization states ($x\&y$-polarization, LCP, and RCP). An array of U-shaped holes constitutes of the high efficiency SPP splitter, and thus the spin-encoded optical logical gates can be achieved. Furthurmore, we prove that a nano-optical conveyor belt can be build up with such U-shaped holes, making the transport of nanoparticles over the film efficiency by transforming between two spin states periodically, and the transport direction switchably along with the $\ce{VO2}$ phase.