  Bell nonlocality refers to correlations between two distant, entangled
particles that challenge classical notions of local causality. Beyond its
foundational significance, nonlocality is crucial for device-independent
technologies like quantum key distribution and randomness generation.
Nonlocality quickly deteriorates in the presence of noise, and restoring
nonlocal correlations requires additional resources. These often come in the
form of many instances of the input state and joint measurements, incurring a
significant resource overhead. Here, we experimentally demonstrate that single
copies of Bell-local states, incapable of violating any standard Bell
inequality, can give rise to nonlocality after being embedded into a quantum
network of multiple parties. We subject the initial entangled state to a
quantum channel that broadcasts part of the state to two independent receivers
and certify the nonlocality in the resulting network by violating a tailored
Bell-like inequality. We obtain these results without making any assumptions
about the prepared states, the quantum channel, or the validity of quantum
theory. Our findings have fundamental implications for nonlocality and enable
the practical use of nonlocal correlations in real-world applications, even in
scenarios dominated by noise.
