Quantum versus classical correlations in Gaussian states.

Journal article

Quantum discord, a measure of genuinely quantum correlations, is generalized to continuous variable systems. For all two-mode Gaussian states, we calculate analytically the quantum discord and a related measure of classical correlations, solving an optimization over all Gaussian measurements. Almost all two-mode Gaussian states are shown to have quantum correlations, while for separable states, the discord is smaller than unity. For a given amount of entanglement, it admits tight upper and lower bounds. Via a duality between entanglement and classical correlations, we derive a closed formula for the Gaussian entanglement of formation of a family of three-mode Gaussian states.

Authors: Adesso, G; Datta, A

• Publication status: Published
• Journal: Physical Review Letters
• Volume: 105
• Issue: 3
• Pages: 030501
• Publication date: 2010-07-01
• DOI: 10.1103/physrevlett.105.030501
• EISSN: 1079-7114
• ISSN: 0031-9007
• Language: English