Long distance quantum teleportation of qubits from photons at 1300 nm to photons at 1550 nm wavelength

Elementary 2-dimensional quantum states (qubits) encoded in 1.3 µm wavelength photons are teleported onto 1.55 µm photons. The use of telecommunication wavelengths enables to take ad-vantage of standard optical fibre and permits to teleport from one lab to a distant one, 55 m away, connected by 2 km of fibre. A teleportation fidelity of 81.2 % is reported. This is large enough to demonstrate the principles of quantum teleportation, in particular that entanglement is exploited. This experiment constitutes a first step towards a quantum repeater.