Experimental entanglement swapping through single-photon χ⁽²⁾ nonlinearity.

ABSTRACT: In photonic quantum information processing, quantum operations using nonlinear photon-photon interactions are vital for implementing two-qubit gates and enabling faithful entanglement swapping. However, due to the weak interaction between single photons, the all-photonic realization of such quantum operations has remained out of reach so far. Herein, we demonstrate an entanglement swapping using sum-frequency generation between single photons in a χ⁽²⁾-nonlinear optical waveguide. We show that a high signal-to-noise ratio (SNR), stable sum-frequency-generation-based entanglement heralder with an ultralow-dark-count superconducting single-photon detector can satisfy the unprecedented SNR requirement indispensable for the swapping protocol. Furthermore, the system clock is enhance

SUBMITTER: Tsujimoto Y 

PROVIDER: S-EPMC12504699 | biostudies-literature | 2025 Oct

REPOSITORIES: biostudies-literature