Engineering energy-time entanglement from resonance fluorescence

Jian Wang; Xiu-Bin Liu; Ziqi Zeng; Xu-Jie Wang; Carlos Antón-Solanas; Li Liu; Hanqing Liu; Haiqiao Ni; Zhichuan Niu; Bang Wu; Zhiliang Yuan

arXiv · 2603.25341

Engineering energy-time entanglement from resonance fluorescence

Jian Wang·Xiu-Bin Liu·Ziqi Zeng·Xu-Jie Wang·Carlos Antón-Solanas·Li Liu·Hanqing Liu·Haiqiao Ni·Zhichuan Niu·Bang Wu·Zhiliang Yuan

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Abstract

Resonance fluorescence from a coherently driven two-level emitter is a minimal quantum optical field that combines phase coherence with single-photon-level nonlinearity. Here we show that it can be engineered, using only passive linear interferometry, into energy-time entanglement. By injecting resonance fluorescence from a single quantum dot into an asymmetric Mach--Zehnder interferometer operated near destructive interference of the single-photon component, we generate an output field whose coincidence statistics are dominated by the simultaneous two-photon contribution |2> and the temporally separated photon-pair contribution |11>. In a Franson geometry, these two sectors are resolved on the coincidence-delay axis, and both exhibit high-visibility nonlocal interference fringes and violate the Clauser--Horne--Shimony--Holt Bell inequality. Our results reveal a general route for engineering entanglement from resonance fluorescence using passive optics.

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Jian Wang, Xiu-Bin Liu, Ziqi Zeng, Xu-Jie Wang, Carlos Antón-Solanas, Li Liu, Hanqing Liu, Haiqiao Ni, Zhichuan Niu, Bang Wu, Zhiliang Yuan. 2026-03-26. Engineering energy-time entanglement from resonance fluorescence. https://arxiv.org/abs/2603.25341

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