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arXiv · 2006.08449

Quantum-enhanced interferometry with large heralded photon-number states

G. S. Thekkadath·M. E. Mycroft·B. A. Bell·C. G. Wade·A. Eckstein·D. S. Phillips·R. B. Patel·A. Buraczewski·A. E. Lita·T. Gerrits·S. W. Nam·M. Stobińska·A. I. Lvovsky·I. A. Walmsley
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Abstract

Quantum phenomena such as entanglement can improve fundamental limits on the sensitivity of a measurement probe. In optical interferometry, a probe consisting of $N$ entangled photons provides up to a $\sqrt{N}$ enhancement in phase sensitivity compared to a classical probe of the same energy. Here, we employ high-gain parametric down-conversion sources and photon-number-resolving detectors to perform interferometry with heralded quantum probes of sizes up to $N=8$ (i.e. measuring up to 16-photon coincidences). Our probes are created by injecting heralded photon-number states into an interferometer, and in principle provide quantum-enhanced phase sensitivity even in the presence of significant optical loss. Our work paves the way towards quantum-enhanced interferometry using large entangled photonic states.

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G. S. Thekkadath, M. E. Mycroft, B. A. Bell, C. G. Wade, A. Eckstein, D. S. Phillips, R. B. Patel, A. Buraczewski, A. E. Lita, T. Gerrits, S. W. Nam, M. Stobińska, A. I. Lvovsky, I. A. Walmsley. 2020-06-15. Quantum-enhanced interferometry with large heralded photon-number states. https://doi.org/10.1038/s41534-020-00320-y

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