Friday, February 6, 2009

Nanodot Advance Threatens Moore's Law

This item from the Edmonton Journal is of great interest. We have suddenly able to trap one or two electrons or whatever is meant as a particle in this story. This is a long awaited threshold because again with a small number of active electrons, the ability to manipulate rises sharply.

Also it suggests that we have finally found the limits of Moore’s Law, at least as far as devices working with electrons. It has been an amazing fifty years or so. And now for our next trick?

This is a fine result and I hope that we are picking up fabrication methods. We now need an overview article on where we are with exactly that. Single layer graphene sheets with electron holes sound possible today. I would like to see a carbon lattice with cut outs produced that can be stacked with successively smaller cut outs to create wells. I would like to see these wells interacting with photons. I fear we are still a ways off yet.

It is clear that we are now on the way to truly superior processors that will have the capacity to support the holodeck of Star Trek fame.

Find may revolutionize computers

U of A breakthough in nanotechnology redefines 'small'
By Keith Gerein, The Edmonton Journal February 3, 2009

Robert Wolkow led a team of U of A nanotechnology experts that discovered new, energy-efficient quantum dots.

Scientists at Edmonton's National Institute for Nanotechnology have made a significant breakthrough that could help pave the way for new generations of smaller, more energy-efficient computers.

The team, led by Robert Wolkow, has invented the world's smallest quantum dots, atom-sized devices capable of controlling electrons, using a fraction of the power of current computer technology.

"Roughly speaking, we predict there could be a 1,000-time reduction in power consumption with electronic computers built in this new way," said Wolkow, a physicist at the University of Alberta.

"And they could be something like 1,000 times smaller in size. So it's reaching the very limit as far as anyone could imagine of how small things could get."

The team's work is published in the latest edition of Physical Review Letters, considered the world's premier physics journal.

Current computers use transistors, which are essentially valves for flowing streams of electrons around a circuit. In recent years, engineers have found ways to make these devices smaller, but pushing electrons through narrow spaces raises the danger of the machines overheating and failing.

"So the problem is no longer how do we make it smaller, it's how do we consume less power," Wolkow said.

His team's development is timely, because the new technology largely eliminates the need for electron flow and instead makes use of a wave-like phenomenon to transmit information, he said.

As a crude analogy, Wolkow described a scenario in which two people are standing at opposite ends of a calm pool and one person drops a pebble in the water. A tiny wave eventually moves across the pool, sending information about the pebble to the other person.

"The energy required to do that would be rather minimal instead of hefting a pipe full of water and pushing the water through it," Wolkow said.

"You don't have to flow millions and millions of uncountable electrons through wires or pipes to transmit information."

This is where the quantum dots, which are essentially vessels or "bottles" for electrons, come in.

Previously developed quantum dots range in size from two to 10 nanometres -- a nanometre is one-billionth of a metre -- and contain groupings of 1,000 or more atoms. Although very tiny, those vessels are still large enough to allow the electrons to dash around in ways too varied to be controlled. Only lowering the temperature to ultra-cold extremes provides any measure of control, and this is impractical.

The quantum dot developed by Wolkow's team is much smaller; less than a nanometre in diameter and containing only one or two particles.

The advantage of such a minuscule environment is that the electrons have few choices in how to behave. As such, their motions and interactions can be more easily harnessed to transmit information, even at room temperature.

"By having this tiniest quantum dot, we have created a way that allows the normally complex interactions among electrons to be distilled down to a controllable and useful level."

The discovery is a highly anticipated milestone in nanotechnology circles.

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