Probabilistic metrology or how some measurement outcomes render ultra-precise estimates
Abstract
We show on theoretical grounds that, even in the presence of noise, probabilistic measurement strategies (which have a certain probability of failure or abstention) can provide, upon a heralded successful outcome, estimates with a precision that exceeds the deterministic bounds for the average precision. This establishes a new ultimate bound on the phase estimation precision of particular measurement outcomes (or sequence of outcomes). For probe systems subject to local dephasing, we quantify such precision limit as a function of the probability of failure that can be tolerated. Our results show that the possibility of abstaining can set back the detrimental effects of noise.
Cite
@article{arxiv.1610.08272,
title = {Probabilistic metrology or how some measurement outcomes render ultra-precise estimates},
author = {J. Calsamiglia and B. Gendra and R. Munoz-Tapia and E. Bagan},
journal= {arXiv preprint arXiv:1610.08272},
year = {2016}
}
Comments
Improved version of arXiv:1407.6910 with an extended introduction where we clarify our approach to metrology, and probabilistic metrology in particular. Changed title