2012/08/31 by Fulin Zhang, Fu-Lin Zhang, Jing-Ling Chen +3 · 32 citations
Computer Science · Mathematics · Physics and Astronomy · Psychology · #Cognitive dissonance #Computer science #Law #Mathematics #Physics #Psychology #Quantum #Quantum Computing Algorithms and Architecture #Quantum Information and Cryptography #Quantum Mechanics and Applications #Quantum discord #Quantum entanglement #Quantum information #Quantum mechanics #Quantum state #Qubit #Statistical physics #Unitary state #quant-ph
paper · pdf · doi:10.1038/srep02134
published in Scientific Reports 3(1), 2134 (Nature Portfolio) · 5 figures, 6 pages. Accepted by Scientific Reports
arxiv created 2013/06/14 · openalex publication_date 2013/07/04 · arxiv updated 2015/03/20 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/06
A fundamental problem in quantum information is to explore what kind of quantum correlations is responsible for successful completion of a quantum information procedure. Here we study the roles of entanglement, discord, and dissonance needed for optimal quantum state discrimination when the latter is assisted with an auxiliary system. In such process, we present a more general joint unitary transformation than the existing results. The quantum entanglement between a principal qubit and an ancilla is found to be completely unnecessary, as it can be set to zero in the arbitrary case by adjusting the parameters in the general unitary without affecting the success probability. This result also shows that it is quantum dissonance that plays as a key role in assisted optimal state discrimination and not quantum entanglement. A necessary criterion for the necessity of quantum dissonance based on the linear entropy is also presented. PACS numbers: 03.65.Ta, 03.67.Mn, 42.50.Dv.