2001/02/28 by Antonio Acín, A. Acin
Computer Science · Physics and Astronomy · #Neural Networks and Applications #Quantum Computing Algorithms and Architecture #Quantum Information and Cryptography #quant-ph
paper · pdf · doi:10.1103/physrevlett.87.177901
published as Phys. Rev. Lett 87, 177901 (2001). · 6 pages, REVTEX. The perfect distinguishability result is extended to any finite set of gates
arxiv created 2001/03/07 · openalex publication_date 2001/10/04 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
The problem of distinguishing two unitary transformations, or quantum gates, is analyzed and a function reflecting their statistical distinguishability is found. Given two unitary operations, U1 and U2, it is proved that there always exists a finite number N such that U(x in circle N)(1) and U(x in circle N)(2) are perfectly distinguishable, although they were not in the single-copy case. This result can be extended to any finite set of unitary transformations. Finally, a fidelity for one-qubit gates, which satisfies many useful properties from the point of view of quantum information theory, is presented.