The importance of using the averaged mutual information when quantifying quantum objectivity

Abstract

In the context of quantum objectivity, a standard way to quantify the classicality of a state is via the mutual information between a system and different fractions of its environment. Many of the tools developed in the relevant literature to quantify quantum objectivity via quantum mutual information rely on the assumption that information about the system leaks symmetrically into its environment. In this work, we highlight the importance of taking this assumption into account, and in particular, analyse how taking non-averaged quantum mutual information as a quantifier of quantum objectivity can be severely misleading whenever information about the system is encoded into the environment in a non-homogeneous way. On the other hand, the averaged mutual information always provides results with a clear operative interpretation.

arXiv comment7 pages, 4 figures, Comments welcome

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Cited by in corpus (4)

• Family of Quantum Mutual Information in Multiparty Quantum Systems
• Bosonic and fermionic mutual information of N-partite systems in dilaton black hole background
• Metrological approach to the emergence of classical objectivity
• Revealing effects of local dimension on variable-range interacting model by connecting Lieb-Robinson bounds and multipartite entanglement