  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.
