2010/09/30 by Xiao-Ming Lu, Jian Ma, Zhengjun Xi +1 · 1 citation
Computer Science · Mathematics · Physics and Astronomy · #Applied mathematics #Law #Mathematical analysis #Mathematics #Physics #Probability distribution #Pure mathematics #Quantum #Quantum Computing Algorithms and Architecture #Quantum Information and Cryptography #Quantum Mechanics and Applications #Quantum discord #Quantum entanglement #Quantum mechanics #Qubit #Statistical physics #Statistics #Unitary state #Upper and lower bounds #Von Neumann architecture #quant-ph
paper · pdf · doi:10.1103/physreva.83.012327
published as Phys. Rev. A 83, 012327 (2011) · 8 pages, 3 figures, version accepted by Phys. Rev. A
arxiv created 2011/01/06 · openalex publication_date 2011/01/31 · arxiv updated 2011/02/09 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
We analyze the optimal measurements to access classical correlations in arbitrary two-qubit states. Two-qubit states can be transformed into the canonical forms via local unitary operations. For the canonical forms, we investigate the probability distribution of the optimal measurements. The probability distribution of the optimal measurements is found to be centralized in the vicinity of a specific von Neumann measurement, which we call the maximal-correlation-direction measurement (MCDM). We prove that, for the states with zero discord and maximally mixed marginals, the MCDM is the optimal measurement. Furthermore, we give an upper bound of quantum discord based on the MCDM, and investigate its performance for approximating the quantum discord.