One step closer to teleportation

Once dismissed by Einstein as “spooky action at a distance,” new research suggests that quantum entanglement may hold the key to eventual teleportation. Researchers from Cambridge University, University College London and the University of Gdansk have, for the first time, worked out how entanglement could be ‘recycled’ to increase the efficiency of these connections. The findings, which are published in Physical Review Letters, could conceivably take us a step close to sci-fi style teleportation in the future. However, the research is purely theoretical.

Sergii Strelchuck from Cambridge’s Department of Applied Mathematics and Theoretical Physics led the research. “Teleportation crucially depends on entanglement, which can be thought as a ‘fuel’ powering it. This fuel, which is contained in the resource state, is hard to generate, store and replenish. Finding a way to use it sparingly, or, ideally, recycling it makes teleportation potentially more usable,” he told Laboratory News.

Teleportation was once considered impossible, but in 1993 a team of scientists calculated that teleportation could work in principle using the quantum laws of entanglement.

Entanglement involves a pair of quantum particles intrinsically bound together. Retaining synchronisation between the particles determines whether the particles are next to each other or on opposing sides of the galaxy. It is through this connection that quantum bits of information (or qubits) can be relayed during traditional forms of classical communication.

Previous teleportation protocols have had various disadvantages and have fallen into one of two camps. Those that could only send scrambled information which required correction from the receiver and more recently “port-based” teleportation which doesn’t require correction, but needs an impractical amount of entanglement – which each object sent would destroy. In this new protocol, multiple qubits can be transported simultaneously.

“The first protocol consists of sequentially teleporting states and the second teleports them in a bulk” said Strelchuck. “We have also found a generalised teleportation technique which we hope will find applications in areas such as quantum computing.”

The researchers say that there is a close connection between teleportation and quantum computers, which are devices that exploit quantum mechanics to perform complex computations.

“In addition to the fuel-efficient teleportation protocol, we also found an entire family of teleportation protocols, and we expect that some of them will have interesting properties and applications.  We hope future work will clarify this, and that some of the protocols will one day be implemented in the lab,” Strelchuck told Laboratory News.

Generalized teleportation and entanglement recycling http://arxiv.org/abs/1209.2683