2025/10/04 by Mohamed ElKabbash, ElKabbash, Mohamed
Computer Science · Physics and Astronomy · #Neural Networks and Reservoir Computing #Mechanical and Optical Resonators #Quantum Information and Cryptography
paper · pdf · doi:10.48550/arxiv.2510.03931
Entanglement witnessing is essential for quantum technologies such as computing, key distribution, and networking. Conventional bulk-optics methods require sequential reconfiguration across multiple polarization bases, limiting efficiency and scalability. We propose a metasurface-based analyzer that performs dual-basis (σz and σy) projections simultaneously by mapping them to orthogonal spatial modes. This allows direct access to the commuting two-photon correlators ⟨ σz ⊗ σz ⟩ and ⟨ σy ⊗ σy ⟩ required for entanglement witnessing. The metasurface design employs meta-atoms engineered to impart independent linear and circular phase delays through anisotropy and geometric control, resulting in polarization-dependent beam deflection that separates H/V and R/L components. This approach halves the measurement overhead compared to sequential analysis while offering a compact, integrable platform for chip-scale quantum photonics. The proposed scheme provides a path toward efficient entanglement verification with applications in quantum key distribution, quantum repeaters, and scalable quantum networks.