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arXiv · 1105.2282

Average output entropy for quantum channels

Christopher King·David K. Moser
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Abstract

We study the regularized average Renyi output entropy $\bar{S}_{r}^{\reg}$ of quantum channels. This quantity gives information about the average noisiness of the channel output arising from a typical, highly entangled input state in the limit of infinite dimensions. We find a closed expression for $β_{r}^{\reg}$, a quantity which we conjecture to be equal to $\Srreg$. We find an explicit form for $β_{r}^{\reg}$ for some entanglement-breaking channels, and also for the qubit depolarizing channel $Δ_λ$ as a function of the parameter $λ$. We prove equality of the two quantities in some cases, in particular we conclude that for $Δ_λ$ both are non-analytic functions of the variable $λ$.

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Christopher King, David K. Moser. 2011-11-21. Average output entropy for quantum channels. https://doi.org/10.1063/1.3658860

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