Unitary-process discrimination with error margin
Abstract
We investigate a discrimination scheme between unitary processes. By introducing a margin for the probability of an erroneous guess, this scheme interpolates the two standard discrimination schemes: minimum-error and unambiguous discrimination. We present solutions for two cases. One is the case of two unitary processes with general prior probabilities. The other is the case with a group symmetry: The processes comprise a projective representation of a finite group. In the latter case, we found that unambiguous discrimination is a kind of “all or nothing”: The maximum success probability is either 0 or 1. We also thoroughly analyze how entanglement with an auxiliary system improves discrimination performance.
- Publication:
-
Physical Review A
- Pub Date:
- June 2010
- DOI:
- 10.1103/PhysRevA.81.062327
- arXiv:
- arXiv:0912.2610
- Bibcode:
- 2010PhRvA..81f2327H
- Keywords:
-
- 03.67.Hk;
- Quantum communication;
- Quantum Physics
- E-Print:
- 9 pages, 3 figures, presentation improved, typos corrected, final version