Demonstration of a quantum teleportation network for continuous variables

Quantum teleportation(1-8) involves the transportation of an unknown quantum state from one location to another, without physical transfer of the information carrier. Although quantum teleportation is a naturally bipartite process, it can be extended to a multipartite protocol known as a quantum teleportation network(9). In such a network, entanglement is shared between three or more parties. For the case of three parties ( a tripartite network), teleportation of a quantum state can occur between any pair, but only with the assistance of the third party. Multipartite quantum protocols are expected to form fundamental components for larger-scale quantum communication and computation(10,11). Here we report the experimental realization of a tripartite quantum teleportation network for quantum states of continuous variables ( electromagnetic field modes). We demonstrate teleportation of a coherent state between three different pairs in the network, unambiguously demonstrating its tripartite character.