Know What's Happening in Nanotech

Ultra-Thin Metasurface Can Generate and Direct Quantum Entanglement

Researchers at Nanjing University and the University of Science and Technology of China have demonstrated an ultra‑thin metasurface that both creates and routes polarization‑entangled photon pairs. The nanostructured silicon‑pillar array converts two orthogonal photons into Bell‑state entanglement across multiple output channels, yielding 21 entangled pairs from seven paths in a single passive element. At only a few tenths of a millimeter wide, the device replaces bulky beam splitters and wave plates, and its pattern can be re‑engineered for more channels. The findings were published in Physical Review Letters.