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arXiv · 1303.2051

Physics behind the minimum of relative entropy measures for correlations

K. Held·N. Mauser
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Abstract

The relative entropy of a correlated state and an uncorrelated reference state is a reasonable measure for the degree of correlations. A key question is however which uncorrelated state to compare to. The relative entropy becomes minimal for the uncorrelated reference state that has the same one-particle density matrix as the correlated state. Hence, this particular measure, coined nonfreeness, is unique and reasonable. We demonstrate that for relevant physical situations, such as finite temperatures or a correlation enhanced orbital splitting, other choices of the uncorrelated state, even educated guesses, overestimate correlations.

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K. Held, N. Mauser. 2013-06-17. Physics behind the minimum of relative entropy measures for correlations. https://doi.org/10.1140/epjb%2Fe2013-40424-5

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