2018/02/28 by Vahid Nassajpour, Seyed Javad Akhtarshenas
Computer Science · Mathematics · Physics and Astronomy · #Algorithm #Bloch sphere #Cluster state #Computer science #Ellipsoid #Mathematical analysis #Mathematics #Measure (data warehouse) #Physics #Quantum #Quantum Computing Algorithms and Architecture #Quantum Information and Cryptography #Quantum Mechanics and Applications #Quantum computer #Quantum correlation #Quantum discord #Quantum entanglement #Quantum mechanics #Quantum state #Qubit #State (computer science) #Statistical physics #Trace distance #Upper and lower bounds #cs.IT #math.IT #quant-ph
paper · pdf · doi:10.1007/s11128-018-2032-5
published in Quantum Information Processing 17(10) (Springer Science+Business Media) · 8 pages, 7 figures
openalex publication_date 2018/08/27 · arxiv created 2018/10/17 · arxiv updated 2018/10/18 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
Any two-qubit state can be represented, geometrically, as an ellipsoid with a certain size and a center located within the Bloch sphere of one of the qubits. Points of this ellipsoid represent the post-measurement states when the other qubit is measured. Based on the most demolition concept in the definition of quantum discord, we study the amount of demolition when the two post-measurement states, represented as two points on the steering ellipsoid, have the most distinguishability. We use trace distance as a measure of distinguishability and obtain the maximum distinguishability for some classes of states, analytically. Using the optimum measurement that gives the most distinguishable steered states, we extract quantum correlation of the state and compare the result with the quantum discord. It is shown that there are some important classes of states for which the most demolition happens exactly at the most distinguished steered points. Correlations gathered from the most distinguished post-measurement states provide a faithful and tight upper bound touching the quantum discord in most of the cases.