2025/04/15 by Xinxin Hu, Gabriele Maron, Hu, Xin-Xin +7 · 2 citations
Computer Science · Engineering · Physics and Astronomy · #FOS: Physical sciences #Mechanical and Optical Resonators #Photonic and Optical Devices #Quantum Information and Cryptography #Quantum Physics (quant-ph)
paper · pdf · doi:10.48550/arxiv.2504.11294
openalex publication_date 2025/04/15 · openalex created_date 2025/10/09 · openalex updated_date 2026/07/31
Photon antibunching in resonance fluorescence - the emission from a single, resonantly driven two-level quantum emitter - is a paradigmatic signature of nonclassical light. Photon entanglement, by contrast, manifests as correlations that can defy any classical description and is typically regarded as a distinct quantum effect. Here, we experimentally extract pairs of narrowband, time-bin-entangled photons from the antibunched resonance fluorescence of a single trapped atom. We verify entanglement via violation of the CHSH Bell inequality and by reconstructing the two-photon density matrix. The observed correlations vanish when the coincidence time window exceeds the antibunching timescale, revealing underlying multimode entanglement in the emitted field. Our results establish a direct link between photon antibunching and photon-photon entanglement, unifying two canonical signatures of nonclassical light.