Long-distance quantum teleportation assisted with free-space entanglement distribution

Faithful long-distance quantum teleportation necessitates priorentanglement distribution between two communicated locations. Theparticle carrying on the unknown quantum information is thencombined with one particle of the entangled states for Bell-statemeasurements, which leads to a transfer of the original quantuminformation onto the other particle of the entangled states. Howeverin most of the implemented teleportation experiments nowadays, theBell-state measurements are performed even before successfuldistribution of entanglement. This leads to an instant collapse ofthe quantum state for the transmitted particle, which is actually asingle-particle transmission thereafter. Thus the true distance forquantum teleportation is, in fact, only in a level of meters. In thepresent experiment we design a novel scheme which has overcome thislimit by utilizing fiber as quantum memory. A complete quantumteleportation is achieved upon successful entanglement distributionover 967 meters in public free space. Active feed-forward controltechniques are developed for real-time transfer of quantuminformation. The overall experimental fidelities for teleportedstates are better than 89.6%, which signify high-qualityteleportation.