Quantum channels that break CHSH nonlocality on all input states are known as CHSH-breaking channels. In quantum networks, such channels are useless for distributing correlations that can violate the CHSH Inequality. Motivated by previous work on activation of nonlocality in quantum states, here we demonstrate an analogous activation of CHSH-breaking channels. That is, we show that certain pairs of CHSH-breaking channels are no longer CHSH-breaking when used in combination. We find that this type of activation can emerge in both uni-directional and bi-directional communication scenarios.

中文翻译：

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CHSH非局域性的通道激活

在所有输入状态上打破 CHSH 非局域性的量子通道被称为 CHSH 破坏通道。在量子网络中，这种通道对于分布可能违反 CHSH 不等式的相关性是无用的。受先前关于激活量子态非定域性的工作的启发，我们在这里展示了 CHSH 破坏通道的类似激活。也就是说，我们表明某些对 CHSH 破坏通道在组合使用时不再是 CHSH 破坏通道。我们发现这种类型的激活可以出现在单向和双向通信场景中。