This technology is an ultra-compact, single, flat, nanostructured surface that acts as a complete quantum state analyzer with the capability of separating photons based on their polarizations and then directing them to a set of outputs. This invention acts as a built-in quantum interferometer for photon pairs and can uniquely identify all four possible quantum states with 100% theoretical accuracy in a single measurement without moving parts or active control. Background: Quantum photonics is a rapidly advancing field at the intersection of quantum information science and nanotechnology. A major focus of this field is on creating and controlling light particles whose quantum states are linked across multiple degrees of freedom. These hyperentangled systems enable efficient quantum communication, computation, and sensing. Similarly, metasurfaces have opened new possibilities for compact and precise light manipulation, replacing bulky optical setups with chip-scale components. The convergence of quantum photonics and metasurface technology is paving the way for scalable quantum devices to reliably and efficiently measure the unique Bell state of pairs of entangled light particles. Photonic quantum technologies are limited by the 50% success rate of existing Bell-state measurement methods. This invention surpasses that limit, enabling more efficient and scalable quantum systems. Applications:
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