The distance record for quantum teleportation has been smashed. Juan Yin and colleagues at the University of Science and Technology of China in Hefei, Anhui, teleported a quantum state 97 kilometres, 81 km further than the previous record.
Yin's team entangle photons – which links their properties even when the photons are separated. Then they beam one photon from each entangled pair to a point A and the other to B.
When a photon is changed at A, the particle at B also changes. No information passes from A to B, but the photon change can be used to partially encode quantum bits, called qubits. Rather like a letter that can't be opened, these can only be reconstructed at B using additional data communicated conventionally from point A, so information is not being sent faster than light.
Teleportation is ultra-secure as there are no photons travelling through space to intercept. The next step would be to teleport with a satellite, for global teleportation, says team member Yuao Chen. That might even lead to a quantum internet.
"This is a very nice piece of work," says Michael Biercuk of the Centre for Engineered Quantum Systems at the University of Sydney, who was not involved in the work.
Source: New Scientist arxiv.org/abs/1205.2024
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