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arXiv · 1707.08792

Experimental ancilla-assisted phase-estimation in a noisy channel

Marco Sbroscia·Ilaria Gianani·Luca Mancino·Emanuele Roccia·Zixin Huang·Lorenzo Maccone·Chiara Macchiavello·Marco Barbieri
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Abstract

The metrological ability of carefully designed probes can be spoilt by the presence of noisy processes occurring during their evolution. The noise is responsible for altering the evolution of the probes in such a way that bear little or no information on the parameter of interest, hence spoiling the signal-to-noise ratio of any possible measurement. Here we show an experiment in which the introduction of an ancilla improves the estimation of an optical phase in the high-noise regime. The advantage is realised by the coherent coupling of the probe and the ancilla at the initialisation and the measurement state, which generate and then select a subset of overall configurations less affected by the noise process.

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Marco Sbroscia, Ilaria Gianani, Luca Mancino, Emanuele Roccia, Zixin Huang, Lorenzo Maccone, Chiara Macchiavello, Marco Barbieri. 2017-07-27. Experimental ancilla-assisted phase-estimation in a noisy channel. https://doi.org/10.1103/physreva.97.032305

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