Entangled Photons Let Researchers "Teleport" Images — Without Ever Putting the Data on the Network

Researchers from the University of the Witwatersrand, Johannesburg, and the Institute of Photonic Sciences, Spain, have published a paper demonstrating how images can be "teleported" across a network — without the information ever physically traveling between nodes.

"Traditionally, two communicating parties physically send the information from one to the other, even in the quantum realm," explains Andrew Forbes, professor and lead principal investigator at Wits University, of the work. "Now, it is possible to teleport information so that it never physically travels across the connection — a 'Star Trek' technology made real."

The team's "teleportation" demonstrated the quantum transportation of image data using two entangled photons — linked through quantum mechanics in such a way that if one changes, so does the other — with a non-linear optical detector. A single photon of the pair, bereft of data, is sent to the node from which the image is to be transmitted — then encoded with the "pattern" of the image, which can be read from the photon's entangled twin at the receiving end. This approach means the image data itself is never found on the network, meaning it can't be eavesdropped upon.

"This protocol has all the hallmarks of teleportation except for one essential ingredient: it requires a bright laser beam to make the non-linear detector efficient, so that the sender could know what is to be sent, but doesn't need to know," Forbes explains. "In this sense, it is not strictly teleportation, but could be in the future if the non-linear detector could be made more efficient."

"We hope that this experiment showing the feasibility of the process motivates further advances in the non-linear optics community through pushing the limits towards a full quantum implementation," adds Adam Vallés, PhD, who co-led the project.

"From a practical point of view, the configuration that we currently demonstrate can already be used to establish a high-dimensional secure channel for quantum communications between two parties, provided that the protocol does not need to be fed with single photons, as would be the case for quantum repeaters.

"We have to be cautious now," Vallés notes, tongue-in-cheek, "as this configuration could not prevent a cheating sender from keeping better copies of the information to be teleported, which means we could end up with many Mr Spock clones in the Star Trek world if that is what Scotty wanted."

The researchers, who named first author Bereneice Sephton, PhD, pictured in this article's main image, as being key in the for the proof-of-concept experiments, have published their findings in the journal Nature Communications under open-access terms.