Long distance quantum teleportation in quantum relay configuration

Dik Bouwmeester, Jian-Wei Pan, Harald Weinfurter +1 more

Hugues de Riedmatten, I. Marcikic, Wolfgang Tittel +3 more

A long distance quantum teleportation experiment with a fiber-delayed Bell state measurement (BSM) is reported. The source creating the qubits to be teleported and the source creating the necessary entangled state are connected to the beam splitter realizing the BSM by two 2 km long optical fibers. In addition, the teleported qubits are analyzed after 2.2 km of optical fiber, in another laboratory separated by 55 m. Time-bin qubits carried by photons at 1310 nm are teleported onto photons at 1550 nm. The fidelity is of 77%, above the maximal value obtainable without entanglement. This is the first realization of an elementary quantum relay over significant distances, which will allow an increase in the range of quantum communication and quantum key distribution.

I. Marcikic, Hugues de Riedmatten, Wolfgang Tittel +3 more

A quantum teleportation over long distances is reported. Alice's unknown quantum state carried by a 1300 nm photon is teleported onto Bob's 1550 nm photon. Bob is situated in another lab connected with the EPR source by 2 km of optical fibres and at a physical distance of 55 m. The Bell state measurement is performed between two photons that travelled through 2 km of optical fibres each. This is a simulation of a transmission of a quantum state over 6 km using quantum teleportation which is the principle of a quantum relay protocol. A fidelity of 77% is obtained which is higher than the fidelity obtained with the best protocol using not entangled particles.

Ri‐Gui Zhou, Xiao-Xue Zhang, Lin-Tao Du

Xiao‐Min Hu, Yu Guo, Bi‐Heng Liu +2 more

Jinjing Shi, Ronghua Shi, Yin Li +2 more

A novel scheme for multi-quantum-state sharing is proposed based on the relay system with teleportation in the non-maximally-entangled channel in order to improve the efficiency of secure distribution of quantum states for communications. Multi quantum states are encoded as quantum packets and teleported from the source to the destination with assistance of the relay. It demonstrates that secure multi quantum states sharing can be achieved and meanwhile the range of quantum communication can be increased and approximately doubled. It provides a valuable application prospect in long distance reliable communications and a wide application to quantum networks.