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arXiv · 1609.01618

Valid lower bound for all estimators in quantum parameter estimation

Jing Liu·Haidong Yuan
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Abstract

The widely used quantum Cramer-Rao bound (QCRB) sets a lower bound for the mean square error of unbiased estimators in quantum parameter estimation, however, in general QCRB is only tight in the asymptotical limit. With a limited number of measurements biased estimators can have a far better performance for which QCRB cannot calibrate. Here we introduce a valid lower bound for all estimators, either biased or unbiased, which can serve as standard of merit for all quantum parameter estimations.

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Jing Liu, Haidong Yuan. 2016-09-06. Valid lower bound for all estimators in quantum parameter estimation. https://doi.org/10.1088/1367-2630%2F18%2F9%2F093009

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