Feeds

EXPOSED: bizarre quantum sibling LOVE TRIANGLE

Bob and Alice get jiggy with Charlie while Randy plays voyeur

Secure remote control for conventional and virtual desktops

University of Waterloo boffins have demonstrated a three-way quantum entanglement that shows quantum non-locality can work with more than two particles.*

The regulars of quantum physics, Bob and Alice, and the interloper Charlie, had an appropriately trailer-trash setting, but alas saw precious little one-on-one photon action since they were separated by hundreds of metres.

The details of the experiment are straightforward enough. To test the three-way “Greenberger-Horne-Zeilinger” (GHZ) state, the researchers started by generating photon triplets in a lab. The triplets were then split up: the first was sent through a 580m optical fibre to delay it; the other two were sent to two trailers (Bob and Charlie) that are 700m distant from both the source and from each other.

Randy, the fourth party in the experiment and located in yet another trailer, randomly selected the measurements Alice (the originating lab) would perform on her photons.

The university's release describes the setup in each location: “Each trailer contained detectors, time-tagging devices developed by IQC spin off company Universal Quantum Devices (UQD), and quantum random number generators. To ensure the locality loophole was closed, the random number generators determined how the photon at each trailer would be measured independently.”

By keeping the time window small – less than three nanoseconds – the university says the experiment can rule out any information transfer between the three locations, “a critical condition to prove the non-locality of entanglement.”

Chris Everen, lead author of the University of Waterloo group's paper in Nature Photonics (abstract here) and now a research assistant at the University of Bristol, says the result means groups of people could create quantum-secured networks rather than simple one-on-one pairings:

“QKD, so far, has been a pairwise system – meaning that it works best and with less assumptions when you’re only talking with one other person. This is the first experiment where you can now imagine a network of people connected in different ways using the correlations between three or more photons,” he said. ®

Bootnote: The author has corrected the first paragraph, which originally referred to faster-than-light entanglement. This was drawn from early wire releases such as this. However, the Waterloo University release focuses on nonlocality.

The Register notes that researchers in China last year claimed that entanglement appears to operate at speeds faster than light. ®

The essential guide to IT transformation

More from The Register

next story
Our LOHAN spaceplane ballocket Kickstarter climbs through £8000
Through 25 per cent but more is needed: Get your UNIQUE rewards!
LOHAN tunes into ultra long range radio
And verily, Vultures shall speak status unto distant receivers
EOS, Lockheed to track space junk from Oz
WA facility gets laser-eyes out of the fog
Volcanic eruption in Iceland triggers CODE RED aviation warning
Lava-spitting Bárðarbunga prompts action from Met Office
NASA to reformat Opportunity rover's memory from 125 million miles away
Interplanetary admins will back up data and get to work
Major cyber attack hits Norwegian oil industry
Statoil, the gas giant behind the Scandie social miracle, targeted
prev story

Whitepapers

Implementing global e-invoicing with guaranteed legal certainty
Explaining the role local tax compliance plays in successful supply chain management and e-business and how leading global brands are addressing this.
Endpoint data privacy in the cloud is easier than you think
Innovations in encryption and storage resolve issues of data privacy and key requirements for companies to look for in a solution.
Why cloud backup?
Combining the latest advancements in disk-based backup with secure, integrated, cloud technologies offer organizations fast and assured recovery of their critical enterprise data.
Consolidation: The Foundation for IT Business Transformation
In this whitepaper learn how effective consolidation of IT and business resources can enable multiple, meaningful business benefits.
High Performance for All
While HPC is not new, it has traditionally been seen as a specialist area – is it now geared up to meet more mainstream requirements?