English

State discrimination with error margin and its locality

Quantum Physics 2009-11-13 v2

Abstract

There are two common settings in a quantum-state discrimination problem. One is minimum-error discrimination where a wrong guess (error) is allowed and the discrimination success probability is maximized. The other is unambiguous discrimination where errors are not allowed but the inconclusive result "I don't know" is possible. We investigate discrimination problem with a finite margin imposed on the error probability. The two common settings correspond to the error margins 1 and 0. For arbitrary error margin, we determine the optimal discrimination probability for two pure states with equal occurrence probabilities. We also consider the case where the states to be discriminated are multipartite, and show that the optimal discrimination probability can be achieved by local operations and classical communication.

Keywords

Cite

@article{arxiv.0804.4349,
  title  = {State discrimination with error margin and its locality},
  author = {A. Hayashi and T. Hashimoto and M. Horibe},
  journal= {arXiv preprint arXiv:0804.4349},
  year   = {2009}
}

Comments

7 pages, 1 figure, typos corrected, references and an appendix added, to appear in Phys. Rev. A 78

R2 v1 2026-06-21T10:35:06.118Z