  Quantum interface links stationary qubits in quantum memory with flying
photonic qubits in optical transmission channels and constitutes a critical
element for future quantum internet. Entanglement of quantum interfaces is a
key step for realization of quantum networks. Through heralded detection of
photon interference, here we generate multipartite entanglement between 25 (or
9) individually addressable quantum interfaces in a multiplexed atomic quantum
memory array and confirm genuine 22 (or 9) partite entanglement, respectively.
Experimental entanglement of a record-high number of quantum interfaces makes
an important enabling step towards realization of quantum networks,
long-distance quantum communication, and multipartite quantum information
processing.
