In classical information theory the conditional probability uniquely defines a classical channel. Introducing a quantum analogue of conditional probability we analyze the mutual information between input and output states of a given quantum channel when the compound state is fully quantum-quantum and classical-quantum. We introduce an analogue of the quantum discord of the channel which measures the distortion of the channel from being classical-quantum. Finally, we generalize our analysis using the mutual information defined via the family of sandwiched Renyi divergencies.

中文翻译：

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量子信道的量子条件概率和测量诱导扰动

在经典信息论中，条件概率唯一地定义了经典通道。引入条件概率的量子模拟，当复合状态是完全量子量子和经典量子时，我们分析给定量子通道的输入和输出状态之间的互信息。我们引入了通道量子不和谐的类似物，它测量通道从经典量子的失真。最后，我们使用通过夹心 Renyi 分歧族定义的互信息来概括我们的分析。