QUANTUM DISCORD AND QUANTUM COMPUTING — AN APPRAISAL
نویسندگان
چکیده
منابع مشابه
Computing quantum discord is NP-complete
We study the computational complexity of quantum discord (a measure of quantum correlation beyond entanglement), and prove that computing quantum discord is NP-complete. Therefore, quantum discord is computationally intractable: the running time of any algorithm for computing quantum discord is believed to grow exponentially with the dimension of the Hilbert space so that computing quantum disc...
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Quantum discord is a measure of the quantumness of correlations. After reviewing its different versions and properties, we apply it to the questions of quantum information processing. First we show that changes in discord in the processed unentangled states indicate the need for entanglement in the distributed implementation of quantum gates. On the other hand, it was shown that zero system-env...
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We extend the quantum discord to continuous variable systems and evaluate Gaussian quantum discord C(ϱ) for bipartite Gaussian states. In particular, for squeezed-thermal states, we explicitly maximize the extractable information over Gaussian measurements: C(ϱ) is minimized by a generalized measurement rather than a projective one. Almost all squeezed-thermal states have nonzero Gaussian disco...
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We present an operational interpretation of quantum discord based on the quantum state merging protocol. Quantum discord is the markup in the cost of quantum communication in the process of quantum state merging, if one discards relevant prior information. Our interpretation has an intuitive explanation based on the strong subadditivity of von Neumann entropy. We use our result to provide opera...
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Quantum discord was proposed as an information theoretic measure of the “quantumness” of correlations. I show that discord determines the difference between the efficiency of quantum and classical Maxwell’s demons in extracting work from collections of correlated quantum systems. Information has an energetic value: It can be converted into work. Maxwell’s demon was introduced into thermodynamic...
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ژورنال
عنوان ژورنال: International Journal of Quantum Information
سال: 2011
ISSN: 0219-7499,1793-6918
DOI: 10.1142/s0219749911008416