Unambiguous comparison of quantum measurements

Details Unambiguous comparison of quantum measurements Unambiguous comparison of quantum measurements

2009-05-27

arxiv.org/abs/0905.4445v1

Phys. Rev. A 80, 052102 (2009)

Physics

Quantum Physics

10 pages, 1 figure

Scientific paper

10.1103/PhysRevA.80.052102

The goal of comparison is to reveal the difference of compared objects as fast and reliably as possible. In this paper we formulate and investigate the unambiguous comparison of unknown quantum measurements represented by non-degenerate sharp POVMs. We distinguish between measurement devices with apriori labeled and unlabeled outcomes. In both cases we can unambiguously conclude only that the measurements are different. For the labeled case it is sufficient to use each unknown measurement only once and the average conditional success probability decreases with the Hilbert space dimension as 1/d. If the outcomes of the apparatuses are not labeled, then the problem is more complicated. We analyze the case of two-dimensional Hilbert space. In this case single shot comparison is impossible and each measurement device must be used (at least) twice. The optimal test state in the two-shots scenario gives the average conditional success probability 3/4. Interestingly, the optimal experiment detects unambiguously the difference with nonvanishing probability for any pair of observables.

Affiliated with

Also associated with

No associations

Rating

Unambiguous comparison of quantum measurements does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Unambiguous comparison of quantum measurements, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Unambiguous comparison of quantum measurements will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-527851