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arXiv · 1410.7415

Weak-value amplification as an optimal metrological protocol

G. Bié Alves·B. M. Escher·R. L. de Matos Filho·N. Zagury·L. Davidovich
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Abstract

The implementation of weak-value amplification requires the pre- and post-selection of states of a quantum system, followed by the observation of the response of the meter, which interacts weakly with the system. Data acquisition from the meter is conditioned to successful post-selection events. Here we derive an optimal post-selection procedure for estimating the coupling constant between system and meter, and show that it leads both to weak-value amplification and to the saturation of the quantum Fisher information, under conditions fulfilled by all previously reported experiments on the amplification of weak signals. For most of the pre-selected states, full information on the coupling constant can be extracted from the meter data set alone, while for a small fraction of the space of pre-selected states, it must be obtained from the post-selection statistics.

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G. Bié Alves, B. M. Escher, R. L. de Matos Filho, N. Zagury, L. Davidovich. 2014-10-27. Weak-value amplification as an optimal metrological protocol. https://doi.org/10.1103/physreva.91.062107

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