Teleportation record heralds secure global network
17:14 15 May 2012 by Michael Slezak
The distance record for quantum teleportationMovie Camera 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.
He adds that one of the next big challenges is to increase the number of qubits processed each minute. Yin's team was able to teleport about five qubits every minute. "If long-distance teleportation is to be exploited in a useful quantum-communication or computing application, the rate of quantum-state transfer will likely need to increase substantially," says Biercuk.
Journal reference: arxiv.org/abs/1205.2024