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Date
2010-12-29Type
- Working Paper
ETH Bibliography
yes
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Abstract
If a quantum system A, which is initially correlated to another system, E, undergoes an evolution separated from E, then the correlation to E generally decreases. Here, we study the conditions under which the correlation disappears completely, resulting in a decoupling of A from E. We give a criterion for decoupling in terms of two smooth entropies, one quantifying the amount of initial correlation between A and E, and the other characterizing the mapping that describes the evolution of A. The criterion applies to arbitrary such mappings and is tight if the mapping satisfies certain natural conditions. Decoupling has a number of applications both in physics and information theory, e.g., as a building block for quantum information processing protocols. As an example, we give a one-shot state merging protocol and show that it is essentially optimal in terms of its entanglement consumption/production. Show more
Publication status
publishedExternal links
Journal / series
arXivPages / Article No.
Publisher
Cornell UniversityOrganisational unit
03781 - Renner, Renato / Renner, Renato
Funding
135048 - Information-theoretic methods for physics (SNF)
258932 - Generalized (quantum) information theory (EC)
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ETH Bibliography
yes
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