Light capture may pave the way for more powerful computers

[RD]

Light capture may pave the way for more powerful computers
10:12 PM August 30

Physicists often complain about the way the phrase "quantum leap" has been cliched and misused by journalists, but perhaps in the case of this story, about quantum computing, they might make an exception.

The remarkable advance in question comes from new research conducted at the Australian National University in Canberra.

It concerns the speed of light, which you may think of as being a constant, around 300,000 kilometres a second.

But researchers at the Laser Physics Centre have set a world record for slowing light down enough to capture it, for over a second, in a crystal.

They say it is a crucial step in the development of the next generation of computers.

Light, according to Dr Matthew Sellars, is very good at transmitting information.

The trouble is it's very, very fast, and it just zips off unless you find a way to hold it for a while.

Dr Sellars and his team are working to develop memory for quantum computing, a new way of storing and processing information that would be drastically faster and more powerful than existing computers.

Using two laser beams and a crystal, the team at the Research School of Physical Sciences and Engineering slowed down the speed of light from 300,000 kilometres per second to a mere few hundred metres per second.

"What we've got is a quantum memory, so it's a place where we can store quantum information and store it for a long time," Dr Sellars said.

"And this stopping light, what we're doing is transferring the quantum information which is on the light, or a complete description of the light field.

"We can now store it on the crystal and hold it there for a long time, for seconds and hopefully longer, and then come back basically just flick a switch, and then recall that quantum information and regenerate the light pulse.

"It should be an exact copy of the pulse that we've put in. So rather than using electrons we'll be using photons, we'll be using light pulses to control our computer system."

The research team is the first to be able to stop light for more than a few milliseconds, and has set a world record.

"The principle thing that we've done is rather than using a gas or a vapour to store the information on, we're using a crystal, and that's the fundamental difference," Dr Sellars said.

Although such research is still in its infancy worldwide, quantum computing would be revolutionary, according to Professor Paul Davies from the Centre for Astrobiology at Macquarie University.

"What it means is that you can carry out a calculation in, as it were two states at once. It's possible to put the information on two, and indeed more than two, on many, many different states at one and the same time, and process that information in parallel," he said.

"That's the great power of quantum computation, it exploits these so-called super-positions of states that atoms can be in more than one state at once, or sometimes in more than one place at once.

"Therefore you have the opportunity of doing massive parallel computation, and then bringing all of these computations together at the end. And so it just gives you a huge increase over the normal computational power of particles."

Professor Davies says there are many ways to exploit quantum super-positions, and that light is just one of them. He says the slowing down of light is all part of trying to gain control over systems at a subatomic level.

"If we could build a fully functioning quantum computer, it would represent an advance on the traditional electronic computer as big as the electronic computer represents over the abacus," he said.

Source: ABC

http://www.optusnet.com.au/news/story/abc/20050831/18/tech/1449604.inp

[Vainglory, Esq.]

Amazing.

[71_deputy]

AND thus paving the way to Star Teks Transporter system!!!!

[Telvis]

I'm still trying to master the internal combustion engine. That stuff is a bit over my head. 

[MoparUSAF]

Faster response time for the site!!!!!
Very cool!!!