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arXiv · 1311.6586

Quantum Metrology via Repeated Quantum Nondemolition Measurements in "Photon Box"

Yu-Ran Zhang·Jie-Dong Yue·Heng Fan
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Abstract

In quantum metrology schemes, one generally needs to prepare $m$ copies of $N$ entangled particles, such as entangled photon states, and then they are detected in a destructive process to estimate an unknown parameter. Here, we present a novel experimental scheme for estimating this parameter by using repeated indirect quantum nondemolition measurements in the setup called "photon box". This interaction-based scheme is able to achieve the phase sensitivity scaling as $1/N$ with a Fock state of $N$ photons. Moreover, we only need to prepare one initial $N$-photon state and it can be used repetitively for $m$ trials of measurements. This new scheme is shown to sustain the quantum advantage for a much longer time than the damping time of Fock state and be more robust than the common strategy with exotic entangled states. To overcome the $2π/N$ periodic error in the estimation of the true parameter, we can employ a cascaded strategy by adding a real-time feedback interferometric layout.

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Yu-Ran Zhang, Jie-Dong Yue, Heng Fan. 2015-04-12. Quantum Metrology via Repeated Quantum Nondemolition Measurements in "Photon Box". https://doi.org/10.1103/physreva.91.022104

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