Discovery brings new type of fast computers closer to reality

Sep 27, 2009
Alex High and Aaron Hammack adjust the optics in their UCSD lab. Credit: UC San Diego

Physicists at UC San Diego have successfully created speedy integrated circuits with particles called "excitons" that operate at commercially cold temperatures, bringing the possibility of a new type of extremely fast computer based on excitons closer to reality.

Their discovery, detailed this week in the advance online issue of the journal Nature Photonics, follows the team's demonstration last summer of an integrated circuit -- an assembly of transistors that is the building block for all electronic devices -- capable of working at 1.5 degrees Kelvin above absolute zero. That temperature, equivalent to minus 457 degrees Fahrenheit, is not only less than the average temperature of deep space, but achievable only in special research laboratories.

Now the scientists report that they have succeeded in building an integrated circuit that operates at 125 degrees Kelvin, a temperature that while still a chilly minus 234 degrees Fahrenheit, can be easily attained commercially with liquid nitrogen, a substance that costs about as much per liter as gasoline.

"Our goal is to create efficient devices based on excitons that are operational at room temperature and can replace electronic devices where a high interconnection speed is important," said Leonid Butov, a professor of physics at UCSD, who headed the research team. "We're still in an early stage of development. Our team has only recently demonstrated the proof of principle for a transistor based on excitons and research is in progress."

Excitons are pairs of negatively charged and positively charged "holes" that can be created by in a semiconductor such as gallium arsenide. When the electron and hole recombine, the exciton decays and releases its energy as a flash of light.

The fact that excitons can be converted into light makes excitonic devices faster and more efficient than conventional with optical interfaces, which use electrons for computation and must then convert them to light for use in communications devices.

"Our transistors process signals using excitons, which like electrons can be controlled with electrical voltages, but unlike electrons transform into photons at the output of the circuit," Butov said. "This direct coupling of excitons to photons allows us to link computation and communication."

Source: University of California - San Diego (news : web)

Explore further: High power laser sources at exotic wavelengths

add to favorites email to friend print save as pdf

Related Stories

Physicists observe new property of matter

Nov 02, 2006

Physicists at the University of California, San Diego have for the first time observed the spontaneous production of coherence within "excitons," the bound pairs of electrons and holes that enable semiconductors ...

Researchers send 'heavy photons' over world-record distances

Jun 21, 2005

Unsurpassed exciton distances, lifetimes may lead to new form of optical communication When light hits a semiconductor material and is absorbed, its photons can become "excitons," sometimes referred to as "heavy photons" ...

Excitons play peek-a-boo on carbon nanotubes

Jun 07, 2007

In the quantum world, photons and electrons dance, bump and carry out transactions that govern everything we see in the world around us. In this week's issue of Science, French and U.S. scientists describe a new technique ...

Recommended for you

High power laser sources at exotic wavelengths

Apr 14, 2014

High power laser sources at exotic wavelengths may be a step closer as researchers in China report a fibre optic parametric oscillator with record breaking efficiency. The research team believe this could ...

Combs of light accelerate communication

Apr 14, 2014

Miniaturized optical frequency comb sources allow for transmission of data streams of several terabits per second over hundreds of kilometers – this has now been demonstrated by researchers of Karlsruhe ...

User comments : 1

Adjust slider to filter visible comments by rank

Display comments: newest first

Husky
4.3 / 5 (3) Sep 27, 2009
What they should do to achieve roomtemperature is using a combo naked graphene (excellent conductor), partially , alternating rows doped graphene (semi conductor) and fully doped graphene (insulater), There you have it, a nanosized roomtemperature transister capable of both very fast massless electron flow as wel as electron/exciton conversion with excellent heat dissipating properties and very low energy needed to drive both the electrons/excitons in the chip

It would be interesting to use such transistor in combo with Intels Light Peak plans for replacing copper interconnects on the mobo andexternal cables...

More news stories

CERN: World-record current in a superconductor

In the framework of the High-Luminosity LHC project, experts from the CERN Superconductors team recently obtained a world-record current of 20 kA at 24 K in an electrical transmission line consisting of two ...

Glasses strong as steel: A fast way to find the best

Scientists at Yale University have devised a dramatically faster way of identifying and characterizing complex alloys known as bulk metallic glasses (BMGs), a versatile type of pliable glass that's stronger than steel.

ESO image: A study in scarlet

This new image from ESO's La Silla Observatory in Chile reveals a cloud of hydrogen called Gum 41. In the middle of this little-known nebula, brilliant hot young stars are giving off energetic radiation that ...

First direct observations of excitons in motion achieved

A quasiparticle called an exciton—responsible for the transfer of energy within devices such as solar cells, LEDs, and semiconductor circuits—has been understood theoretically for decades. But exciton movement within ...

Patent talk: Google sharpens contact lens vision

(Phys.org) —A report from Patent Bolt brings us one step closer to what Google may have in mind in developing smart contact lenses. According to the discussion Google is interested in the concept of contact ...

Warm US West, cold East: A 4,000-year pattern

Last winter's curvy jet stream pattern brought mild temperatures to western North America and harsh cold to the East. A University of Utah-led study shows that pattern became more pronounced 4,000 years ago, ...