2007/12/31 by Mário Ziman, Mario Ziman, Teiko Heinosaari · 1 citation
Computer Science · Mathematics · Physics and Astronomy · #Mathematical Inequalities and Applications #Quantum Information and Cryptography #Quantum Mechanics and Applications #quant-ph
paper · pdf · doi:10.1103/physreva.77.042321
published as Phys. Rev. A 77, 042321 (2008) · 8 pages, no figures
arxiv created 2008/02/18 · openalex publication_date 2008/04/23 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
We address the problem of unambiguous discrimination and identification among quantum observables. We set a general framework and investigate in detail the case of qubit observables. In particular, we show that perfect discrimination with two shots is possible only for sharp qubit observables (e.g., Stern-Gerlach apparatuses) associated with mutually orthogonal directions. We also show that for sharp qubit observables associated to nonorthogonal directions unambiguous discrimination with an inconclusive result is always possible.