2012/01/31 by Swapan Rana, Preeti Parashar · 3 citations
Computer Science · Physics and Astronomy · #Quantum Computing Algorithms and Architecture #Quantum Information and Cryptography #Quantum Mechanics and Applications #quant-ph
paper · pdf · doi:10.1103/physreva.85.024102
published as Phys. Rev. A 85, 024102 (2012) · 4 pages
arxiv created 2012/02/13 · openalex publication_date 2012/02/13 · arxiv updated 2012/02/14 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/29
We use singular value decomposition to derive a tight lower bound for geometric discord of arbitrary bipartite states. In a single shot this also leads to an upper bound of measurement-induced nonlocality which in turn yields that for Werner and isotropic states the two measures coincide. We also emphasize that our lower bound is saturated for all 2\ensuremath\bigotimesn states. Using this we show that both the generalized Greenberger-Horne-Zeilinger and W states of N qubits satisfy monogamy of geometric discord. Indeed, the same holds for all N-qubit pure states which are equivalent to W states under stochastic local operations and classical communication. We show by giving an example that not all pure states of four or higher qubits satisfy monogamy.