Feeds

Boffins build 'slow glass' light-trapping nanodoughnut

Exciton in tight ring = fast photonic computing?

Intelligent flash storage arrays

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). ®

Providing a secure and efficient Helpdesk

More from The Register

next story
GRAV WAVE DRAMA: 'Big Bang echo' may have been grit on the scanner – boffins
Exit Planet Dust on faster-than-light expansion of universe
SpaceX Dragon cargo truck flies 3D printer to ISS: Clawdown in 3, 2...
Craft berths at space station with supplies, experiments, toys
That glass of water you just drank? It was OLDER than the SUN
One MEELLION years older. Some of it anyway
NASA rover Curiosity drills HOLE in MARS 'GOLF COURSE'
Joins 'traffic light' and perfect stony sphere on the Red Planet
Mine Bitcoins with PENCIL and PAPER
Forget Sudoku, crunch SHA-256 algos
Big dinosaur wowed females with its ENORMOUS HOOTER
That's right, Doris, I've got biggest snout in the prehistoric world
Japanese volcano eruption reportedly leaves 31 people presumed dead
Hopes fade of finding survivors on Mount Ontake
Canberra drone team dances a samba in Outback Challenge
CSIRO's 'missing bushwalker' found and watered
prev story

Whitepapers

A strategic approach to identity relationship management
ForgeRock commissioned Forrester to evaluate companies’ IAM practices and requirements when it comes to customer-facing scenarios versus employee-facing ones.
Storage capacity and performance optimization at Mizuno USA
Mizuno USA turn to Tegile storage technology to solve both their SAN and backup issues.
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?
Beginner's guide to SSL certificates
De-mystify the technology involved and give you the information you need to make the best decision when considering your online security options.
Security for virtualized datacentres
Legacy security solutions are inefficient due to the architectural differences between physical and virtual environments.