Quantum teleportation and quantum memory are two crucial elements for large-scale quantum networks. With the help of prior distributed entanglement as a "quantum channel," quantum teleportation provides an intriguing means to faithfully transfer quantum states among distant locations without actual transmission of the physical carriers [Bennett CH, et al. (1993) Phys Rev Lett 70 (13):1895-1899]. Quantum memory enables controlled storage and retrieval of fast-flying photonic quantum bits with stationary matter systems, which is essential to achieve the scalability required for large-scale quantum networks. Combining these two capabilities, here we realize quantum teleportation between two remote atomic-ensemble quantum memory nodes, each composed of ∼10 8 rubidium atoms and connected by a 150-m optical fiber. The spin wave state of one atomic ensemble is mapped to a propagating photon and subjected to Bell state measurements with another single photon that is entangled with the spin wave state of the other ensemble. Two-photon detection events herald the success of teleportation with an average fidelity of 88(7)%. Besides its fundamental interest as a teleportation between two remote macroscopic objects, our technique may be useful for quantum information transfer between different nodes in quantum networks and distributed quantum computing.cold atomic ensembles | long-distance quantum communication | quantum computation | light-matter interface S ingle photons are so far the best messengers for quantum networks as they are naturally propagating quantum bits (qubits) and have very weak coupling to the environment (1, 2). However, due to the inevitable photon loss in the transmission channel, the quantum communication is limited currently to a distance of about 200 km (3, 4). To achieve scalable long-distance quantum communication (5, 6), quantum memories are required (7-10), which coherently convert a qubit between light and matter efficiently on desired time points so that operations can be appropriately timed and synchronized. The connection of distant matter qubit nodes and transfer of quantum information between the nodes can be done by distributing atom-photon entanglement through optical channels and quantum teleportation (11).Optically thick atomic ensemble has been proved to be an excellent candidate for quantum memory (12-17), with promising experimental progress including the entanglement between two atomic ensembles (18, 19), generation of nonclassical fields (12, 13), efficient storage and retrieval of photonic qubits (14), subsecond storage time (17), and demonstration of a preliminary quantum repeater node (15,16). Quantum teleportation has been demonstrated with single photons (20)(21)(22), from light to matter (23,24), and between single ions (25-27). However, quantum teleportation between remote atomic ensembles has not been realized yet.In this article, we report a teleportation experiment between two atomic-ensemble quantum memories. The layout of our experiment is shown in Fig. 1. Two atomic e...
