Optimized Quantum Teleportation Protocol More 'Fuel Efficient'

Quantum teleportation is possibly becoming more efficient! Mathematicians worked out a paper titled "Generalized Teleportation and Entanglement Recycling", in which they propose a new, more efficient protocol for teleportation which allows for a wide variety of potential applications in quantum physics.

The researchers have worked out how entanglement could be 'recycled' to increase the efficiency of these connections and will publishe their paper in the journal Physical Review Letters.

A team of scientists calculated in 1993 that teleportation could work in principle using quantum laws, a feat previously considered impossible. Entanglement involves a pair of quantum particles such as electrons or protons that are intrinsically bound together, retaining synchronisation between the two that holds whether the particles are next to each other or on opposing sides of a galaxy. Through this connection, quantum bits of information - qubits - can be relayed securely using plain forms of everyday digital communication.

Previous teleportation protocols, have fallen into one of two camps, those that could only send scrambled information requiring correction by the receiver, or more recently, "port-based" teleportation that doesn't require a correction, but needed an impractical amount of entanglement - each object sent would destroy the entangled state.

Now, physicists from Cambridge, University College London, and the University of Gdansk have developed a protocol to provide an optimal solution in which the entangled state is 'recycled', so that the gateway between particles holds for the teleportation of multiple objects.

They have even devised a protocol in which multiple qubits can be teleported simultaneously, although the entangled state degrades proportionally to the amount of qubits sent in both cases.

"The first protocol consists of sequentially teleporting states, and the second teleports them in a bulk," said Sergii Strelchuck from Cambridge's Department of Applied Mathematics and Theoretical Physics, who led the research with colleagues Jonathan Oppenheim of Cambridge and UCL and Michal Horodecki of the University of Gdansk.

"We have also found a generalised teleportation technique which we hope will find applications in areas such as quantum computation."

Einstein famously loathed the theory of quantum entanglement, dismissing it as "spooky action at a distance". But entanglement has since been proven to be a very real feature of our universe, and one that has extraordinary potential to advance all manner of scientific (and science-fiction like) endeavor.

"There is a close connection between teleportation and quantum computers, which are devices which exploit quantum mechanics to perform computations which would not be feasible on a classical computer," said Strelchuck.

"Building a quantum computer is one of the great challenges of modern physics, and it is hoped that the new teleportation protocol will lead to advances in this area."

The Cambridge physicists' protocol presented here is a theoretical work, but there a many experiments going on that work very well. Very recently, a team of Chinese scientists reported beaming entangled photons with a laser 143km across a lake, which will become a feasible way to transport the required entangled particles over long distances in order to use them for 100% secure communications.

Quantum entanglement is increasingly seen as an important area of scientific investment. Adds Strelchuck: "Entanglement can be thought of as the fuel, which powers teleportation. Our protocol is more fuel efficient, able to use entanglement thriftily while eliminating the need for error correction."

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