Quantum computer draws closer

Sava · May 21, 2003, 16:53

Quote:

Quantum computer draws closer
By Dr David Whitehouse
BBC News Online science editor

Scientists have "entangled" two sub-atomic particles separated by about a millimetre, a feat that might pave the way for powerful quantum computers in the future.

When two particles are entangled they are somehow connected because the fate of one depends upon the other, no matter how far apart they are.
Sounds weird - even Einstein never quite came to terms with it.

Entangled particles may be useful to make logic circuits for computers that have a far greater capacity and speed than today's machines.

Published in the journal Science, the results represent the latest advance in a broad scientific effort to apply properties of quantum physics to the creation of a new generation of supercomputers.

Bothering Einstein

Quantum entanglement (QE) describes the situation when the fates of two or more particles become bound together.

A change in one entangled particle results in an instant change in the other particle, no matter how far away it is - even if it is at the opposite end of the Universe.

Of course, it is not quite a simple as that. The phenomenon is linked in a deep way to the fundamental properties of matter and the nature of observing and measuring reality.

It really bothered Einstein, especially since the concept that a change in one particle was somehow communicated to the other faster than the speed of light - nature's ultimate speed limit.

He called it "spooky action at a distance".

Speed limits

He believed there was something profound in the phenomenon and that buried in its seeming absurdity lay something that could overthrow quantum mechanics - a successful theory of the way the Universe behaves on the atomic and sub-atomic level.

Einstein was not alive when, in the 1970's, physicist Alan Aspect carried out an experiment that showed QE was real and could form the basis for the computers, not of tomorrow, but of the day after.

Today's computers are limited by the speed of electrons as they move around integrated circuits.

In the future, computers that use light instead of electrons will be faster as they will be limited by the speed of light passing through crystals. But even lightspeed may be supplanted.

Best yet

According to some, a computer based on quantum entanglement would not be bound by those limits as it would use "spooky action at a distance" instead of electrons or photons.

A quantum computer would have to "entangle" quantum bits - or qubits - over significant distances. However, particle entanglement has only been observed on the micrometre (millionth of a metre) scale so far.

Now, Andrew Berkley and colleagues from the University of Maryland, US, have entangled two qubits inside a silicon chip over a distance of 0.7 millimetres - a thousand times greater.

A millimetre does not sound like the opposite ends of the Universe but it is significantly closer to the scale needed to build quantum mechanical computer components.

"Entanglement is essential to quantum computing because it is the linked quality that builds more information into quantum bits than is possible with classical computing bits," says Andrew Berkley.

"Our current findings, which build on the work of many others, moves us further along the road towards a quantum computer," he adds.

Story from BBC NEWS:
http://news.bbc.co.uk/go/pr/fr/-/2/h...re/3043731.stm

Published: 2003/05/21 19:29:25 GMT

Interesting. I wasn't aware that Quantum particles and their effects were faster than light. I'm glad to see the speed of light isn't such a limit as Einstein proposed. Now... I must ask... WHEN AM I GETTING MY QUANTUM COMPUTER!?

reds4ever · May 21, 2003, 17:02

Sinclair made one in the late 80's (in name only) ;O)

Japher · May 21, 2003, 17:03

Boggles the mind.

Quote:

When two particles are entangled they are somehow connected because the fate of one depends upon the other, no matter how far apart they are.

I do love it when scientists use words like things and stuff, but fate? That's a new one...

Az · May 21, 2003, 17:05

This stuff is eons away from a computer.

when it actually calculates something, call me.

Cruddy · May 21, 2003, 18:09

Hmm... I think Azazel is right, this is a long way from a production line.

On the bright side, light induced switches are being well researched.

I don't think we'll see a quantum PC in the next 30 years, but a photonic one might happen in that time frame. The tricky bit is going to be evolving RAM that works at those speeds. And of course, it's going to be mainframe first.

Kuciwalker · May 21, 2003, 18:11

Actually, scientists built a quantum computer that added two numbers together, I think 5 and 7.

Sava · May 21, 2003, 18:12

I can't wait for the kind of porn that will be on Quantum computers!

Kuciwalker · May 21, 2003, 18:14

It wouldn't be any different

The first applications of quantum computers would be codebreaking. Their strength is their ability to fall into the right solution, rather than evaluate every possible solution sequentially.

Aro · May 21, 2003, 18:15

Quote:

Originally posted by skywalker
Actually, scientists built a quantum computer that added two numbers together, I think 5 and 7.

I read something about that a few weeks ago...

Sava · May 21, 2003, 18:18

Quote:

It wouldn't be any different

I think the technological improvements would allow higher resolutions and holographic presentations of porn... that would definitely be better spank material!

realpolitic · May 21, 2003, 18:27

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Originally posted by Cruddy
Hmm... I think Azazel is right, this is a long way from a production line.

Back in the late '80s I was interviewed for a job with an "Xray lithography" group, The short wavelengths would make thinner circuits, but short wavelengths means higher energy, which can destroy the silicon substrate. To my knowledge, today's state of the art is soft ultraviolet.

Also, fusion was said to be 10 years away since the 50's, and and AI program which called itself "The General Problem Solver" was attempted in the '50s.

Zero · May 21, 2003, 18:44

Quote:

Originally posted by skywalker
It wouldn't be any different

The first applications of quantum computers would be codebreaking. Their strength is their ability to fall into the right solution, rather than evaluate every possible solution sequentially.

i think he meant downloading it

Sava · May 21, 2003, 18:45

Downloading and quality

solar · May 21, 2003, 18:58

Quantum computers have also factored 15.

Lorizael · May 21, 2003, 19:03

Fusion exists. We're just too afraid to spend the money to make it feasible. We've operated fusion reactors without monstrously bad things happening.

Kuciwalker · May 21, 2003, 19:07

Quote:

Originally posted by Sava
I think the technological improvements would allow higher resolutions and holographic presentations of porn... that would definitely be better spank material!

The difficulty with holographic video isn't computing power... not in the least. It's the hardware - no one has developed a usable holographic projector.

Skanky Burns · May 21, 2003, 22:25

Fusion reactors as a source of electricty haven't been demonstrated yet. So far they haven't produced more energy than was used to start them up.

War4ever · May 21, 2003, 22:53

the odds of the public getting their hands on a quantum computer anytime soon, are.....slim to nil

Urban Ranger · May 22, 2003, 00:03

Quote:

Originally posted by realpolitic
Back in the late '80s I was interviewed for a job with an "Xray lithography" group, The short wavelengths would make thinner circuits, but short wavelengths means higher energy, which can destroy the silicon substrate. To my knowledge, today's state of the art is soft ultraviolet.

I don't think x-ray destroys silicon, it take a bit more than that. The real problem is x-ray can't be focused with lenses like UV.

Sava · May 22, 2003, 00:06

Quote:

Originally posted by skywalker

The difficulty with holographic video isn't computing power... not in the least. It's the hardware - no one has developed a usable holographic projector.

But I don't want my chicks all polygonal and sh1t!