  We present a convenient and efficient way to exchange and distribute
multipartite entangled state via atomic coherence induced by
electromagnetically induced transparency (EIT) in an atomic ensemble. By using
the EIT-based nondegenerate four-wave mixing processes, the generation,
exchange, and distribution of light-light, atom-light, and atom-atom
multipartite entanglement can be achieved in a deterministic way with only
coherent light fields. This EIT-induced atomic coherence acts as a quantum
information processor and has the function of quantum beam splitter, quantum
frequency converter, quantum entangler, and quantum repeater, which greatly
facilitates the operations in quantum information processing, and holds
promising applications in realistic scalable quantum communication and quantum
networks
