Feeds

Boffins build 'slow glass' light-trapping nanodoughnut

Exciton in tight ring = fast photonic computing?

High performance access to file storage

Warwickshire boffins believe they may be on the track of science-fiction "slow glass", through which light might take a long time to travel. The scientists think that such light-storing materials might be fashioned using excitons mounted inside unfeasibly tiny "quantum doughnuts".

In essence it seems that an exciton is an electron which has been jazzed up a bit energy-wise by absorbing a photon of light. The idea is that if you could prevent such excitons immediately re-emitting their photons and so turning back into electrons at once as they normally do, you could effectively store, or "freeze" light.

Such technology was imagined by renowned sci-fi scribe Robert Shaw in his novel Other Days, Other Eyes and its precursor works. "Slow Glass", through which light would take hours, days or years to travel, was used for many things in the book: stored daylight offered free lighting, for instance. (The omnipresence of slow-glass lights also delivered an equivalent of a CCTV panopticon, as images of anything happening within view of a pane of slow glass would later be visible on its other side.)

According to Warwickshire physicists Andrea Fischer and Rudolf A. Roemer, excitons - properly handled - could offer something on these lines, and might also be extremely handy in light-based (photonic) computing. With electronics approaching its limits, many researchers believe that photonics could deliver the next wave of big performance increases.

Normally an exciton, fairly uselessly, simply releases its photon almost at once. But Fischer and Roemer, trying out notions one day in the lab, decided to try slotting excitons into some quantum nano-doughnuts they had lying around.

Such "Aharonov-Bohm nano rings" were originally created as a by-product of manufacturing comparatively humdrum quantum dots. It seems that sometimes even the most skilful boffin, knocking out a batch of quantodots in a hurry, will inadvertently splash the material onto the receiving surface too hard and make a doughnut rather than a contiguous nano-blob dot.

Fischer and Roemer decided to slot an exciton into the middle of such a nano-ring, in the 10-100 nm size range. That in itself - as one would naturally expect - achieved nothing. But the addition of "a combination of magnetic and electric fields" makes it possible to trap the slippery exciton in one's unfeasibly minuscule quantum ring, at which point it is entirely at one's bidding. The exciton can then be made to hold onto its photon, "freezing" it in place, or collapse back in electronhood and emit the light on command.

"This has significant implications for the development of light based computing," says Roemer.

Though other scientists have slowed light down using various techniques which might also be significant in the possible future wave of photonic IT, Roemer and Fischer consider that theirs is the first which properly locks a photon down for release on demand.

The Warwickshire brainboxes, allied with others, publish their paper Exciton storage in a nanoscale Aharonov-Bohm ring with electric field tuning here (subscription required). ®

High performance access to file storage

More from The Register

next story
Elon Musk's LEAKY THRUSTER gas stalls Space Station supply run
Helium seeps from Falcon 9 first stage, delays new legs for NASA robonaut
Solar-powered aircraft unveiled for round-the-world flight
It's going to be a slow and sleepy flight for the pilots
Russian deputy PM: 'We are coming to the Moon FOREVER'
Plans to annex Earth's satellite with permanent base by 2030
LOHAN's Punch and Judy show relaunches Thursday
Weather looking good for second pop at test flights
Saturn spotted spawning new FEMTO-MOON
Icy 'Peggy' looks to be leaving the outer rings
Discovery time for 200m WONDER MATERIALS shaved from 4 MILLENNIA... to 4 years
Alloy, Alloy: Boffins in speed-classification breakthrough
India's GPS alternative launches second satellite
Closed satnav system due to have all seven birds aloft by 2016
Curiosity finds not-very-Australian-shaped rock on Mars
File under 'messianic pastries' and move on, people
Top Secret US payload launched into space successfully
Clandestine NRO spacecraft sets off on its unknown mission
prev story

Whitepapers

Mainstay ROI - Does application security pay?
In this whitepaper learn how you and your enterprise might benefit from better software security.
Five 3D headsets to be won!
We were so impressed by the Durovis Dive headset we’ve asked the company to give some away to Reg readers.
3 Big data security analytics techniques
Applying these Big Data security analytics techniques can help you make your business safer by detecting attacks early, before significant damage is done.
The benefits of software based PBX
Why you should break free from your proprietary PBX and how to leverage your existing server hardware.
Mobile application security study
Download this report to see the alarming realities regarding the sheer number of applications vulnerable to attack, as well as the most common and easily addressable vulnerability errors.