Characterizing entanglement using quantum discord over state extensions
arXiv:2012.03835 · doi:10.1103/PhysRevA.105.012426
Abstract
We propose a framework to characterize entanglement with quantum discord, both asymmetric and symmetric, over state extensions. In particular, we show that the minimal Bures distance of discord over state extensions is equivalent to Bures distance of entanglement. This equivalence places quantum discord at a more primitive position than entanglement conceptually in the sense that entanglement can be interpreted as an irreducible part of discord over all state extensions. Based on this equivalence, we also offer an operational meaning of Bures distance of entanglement by connecting it to quantum state discriminations. Moreover, for the relative entropy part, we prove that the entanglement measure introduced by Devi and Rajagopal [A. R. U. Devi and A. K. Rajagopal, Phys. Rev. Lett. 100, 140502 (2008)] is actually equivalent to the relative entropy of entanglement. We also provide several quantifications of entanglement based on discord measures.
11 pages, 2 figures, close to published version
References in corpus (17)
- Quantum discord and the power of one qubit
- Necessary and sufficient condition for non-zero quantum discord
- Experimental Quantum State Tomography of Optical Fields and Ultrafast Statistical Sampling
- Reference frames, superselection rules, and quantum information
- Interpreting quantum discord through quantum state merging
- Operational interpretations of quantum discord
- Linking Quantum Discord to Entanglement in a Measurement
- All non-classical correlations can be activated into distillable entanglement
- Quantum discord bounds the amount of distributed entanglement
- Conservation law for distributed entanglement of formation and quantum discord
- Quantum cost for sending entanglement
- Entanglement irreversibility from quantum discord and quantum deficit
- Linking a distance measure of entanglement to its convex roof
- An additive and operational entanglement measure: conditional entanglement of mutual information
- Quantum correlations and distinguishability of quantum states
- Generalized information theoretic measure to discern the quantumness of correlations
- Global Quantum discord of multi-qubit states