A trick for transferring quantum information from atoms to photons and back again could be used to create impenetrable global communication networks and computers that work at astounding speeds.

Two research groups, one led by Mikail Lukin at Harvard University and the second headed by Alex Kuzmich of Georgia Institute of Technology, both in the US, separately demonstrated the feat using similar methods.

Both teams employed powerful laser pulses to extract quantum information from a cloud of atoms in the form of a single photon. That photon was then transmitted through a normal optical fibre before its quantum state was transferred to a second atomic cloud.

Creating communication links between such “quantum memories” – the clouds of atoms – is crucial to building complex networks that exploit quantum phenomena, such as entanglement and superposition. Quantum networks are extremely sensitive to interference, but hold great promise for secure communications and superfast computing…