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arXiv · 2504.11294

On the Relationship Between Antibunching and Entanglement in Resonance Fluorescence

Xin-Xin Hu·Gabriele Maron·Luke Masters·Arno Rauschenbeutel·Jürgen Volz
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Abstract

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.

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Xin-Xin Hu, Gabriele Maron, Luke Masters, Arno Rauschenbeutel, Jürgen Volz. 2025-04-15. On the Relationship Between Antibunching and Entanglement in Resonance Fluorescence. https://arxiv.org/abs/2504.11294

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