Weak-value amplification as an optimal metrological protocol
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.
Cite
@article{arxiv.1410.7415,
title = {Weak-value amplification as an optimal metrological protocol},
author = {G. Bié Alves and B. M. Escher and R. L. de Matos Filho and N. Zagury and L. Davidovich},
journal= {arXiv preprint arXiv:1410.7415},
year = {2015}
}