Feeds

EXPOSED: bizarre quantum sibling LOVE TRIANGLE

Bob and Alice get jiggy with Charlie while Randy plays voyeur

The Power of One Infographic

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. ®

Eight steps to building an HP BladeSystem

More from The Register

next story
Malaysian Airlines flight MH17 claimed lives of HIV/AIDS cure scientists
Researchers, advocates, health workers among those on shot-down plane
Forty-five years ago: FOOTPRINTS FOUND ON MOON
NASA won't be back any time soon, sadly
Mwa-ha-ha-ha! Eccentric billionaire Musk gets his PRIVATE SPACEPORT
In the Lone Star State, perhaps appropriately enough
MARS NEEDS OCEANS to support life - and so do exoplanets
Just being in the Goldilocks zone doesn't mean there'll be anyone to eat the porridge
The Sun took a day off last week and made NO sunspots
Someone needs to get that lazy star cooking again before things get cold around here
Diary note: Pluto's close-up is a year from … now!
New Horizons is less than a year from the dwarf planet
Boffins discuss AI space program at hush-hush IARPA confab
IBM, MIT, plenty of others invited to fill Uncle Sam's spy toolchest, but where's Google?
prev story

Whitepapers

Reducing security risks from open source software
Follow a few strategies and your organization can gain the full benefits of open source and the cloud without compromising the security of your applications.
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.
Application security programs and practises
Follow a few strategies and your organization can gain the full benefits of open source and the cloud without compromising the security of your applications.
Boost IT visibility and business value
How building a great service catalog relieves pressure points and demonstrates the value of IT service management.
Consolidation: the foundation for IT and business transformation
In this whitepaper learn how effective consolidation of IT and business resources can enable multiple, meaningful business benefits.