UNCONDITIONAL QUANTUM TELEPORTATION

Quantum teleportation of optical coherent states was demonstrated expe rimentally using squeezed-state entanglement. The quantum nature of th e achieved teleportation was verified by the experimentally determined fidelity F-exp = 0.58 +/- 0.02, which describes the match between inp ut and output states. A fidelity greater than 0.5 is not possible for coherent states without the use of entanglement. This is the first rea lization of unconditional quantum teleportation where every state ente ring the device is actually teleported.