© 2016 IOP Publishing Ltd and Deutsche Physikalische Gesellschaft. 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.
|Journal||New Journal of Physics|
|Publication status||Published - 1 Oct 2016|
- probabilistic maps
- quantum information
- quantum metrology
- quantum statistical inference