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arXiv · 2010.05513

Approximate recoverability and relative entropy II: 2-positive channels of general v. Neumann algebras

Thomas Faulkner·Stefan Hollands
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Abstract

We generalize our results in paper I in this series to quantum channels between general v. Neumann algebras, proving the approximate recoverability of states which undergo a small change in relative entropy through the channel. To this end, we derive a strengthened form of the quantum data processing inequality for the change in relative entropy of two states under a channel between two v. Neumann algebras. Compared to the usual inequality, there is an explicit lower bound involving the fidelity between the original state and a recovery channel.

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Thomas Faulkner, Stefan Hollands. 2020-10-12. Approximate recoverability and relative entropy II: 2-positive channels of general v. Neumann algebras. https://arxiv.org/abs/2010.05513

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