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arXiv · 2408.13817

Quantum-enhanced weak absorption estimation with correlated photons

Zhucheng Zhang·Xue Zhang·Jing Liu·Hui Dong
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Abstract

Conventional absorption spectroscopy relies on coherent laser sources, and in turn suffers from the inherent limitation of shot noise, especially in estimating weak absorption. Here we propose a measurement strategy with correlated photons to determine the weak absorption by distinguishing the output with and without photons, dubbed as the on-off measurement. We demonstrate that absorption spectroscopy that incorporates quantum correlations is capable of estimating weak absorption down to a single-photon level, even in noisy environments, achieving a precision comparable to that obtained through 1000 photons in conventional absorption spectroscopy. Our strategy provides a new method to probe fragile systems with weak absorption, avoiding the occurrence of light-induced damage.

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Zhucheng Zhang, Xue Zhang, Jing Liu, Hui Dong. 2024-08-25. Quantum-enhanced weak absorption estimation with correlated photons. https://doi.org/10.1103/physrevlett.134.133604

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