  Networks composed of independent sources of entangled particles that connect
distant users are a rapidly developing quantum technology and an increasingly
promising test-bed for fundamental physics. Here we address the certification
of their post-classical properties through demonstrations of full network
nonlocality. Full network nonlocality goes beyond standard nonlocality in
networks by falsifying any model in which at least one source is classical,
even if all the other sources are limited only by the no-signaling principle.
We report on the observation of full network nonlocality in a star-shaped
network featuring three independent sources of photonic qubits and joint
three-qubit entanglement-swapping measurements. Our results constitute the
first experimental demonstration of full network nonlocality beyond the bilocal
network.
