Single-Atom Transistor Discovered

[n2doc]

ScienceDaily (Dec. 7, 2009) — Researchers from Helsinki University of Technology (Finland), University of New South Wales (Australia), and University of Melbourne (Australia) have succeeded in building a working transistor, whose active region composes only of a single phosphorus atom in silicon.

The results have just been published in Nano Letters, a journal of the American Chemical Society.

The working principles of the device are based on sequential tunneling of single electrons between the phosphorus atom and the source and drain leads of the transistor. The tunneling can be suppressed or allowed by controlling the voltage on a nearby metal electrode with a width of a few tens of nanometers.

The rapid development of computers, which created the present information society, has been mainly based on the reduction of the size of transistors. Scientists have known for a long time that this development has to slow down critically during the future decades when the even tighter inexpensive packing of transistors would require them to shrink down to the atomic length scales. In the recently developed transistor, all the electric current passes through the same single atom. This allows researchers to study the effects arising in the extreme limit of the transistor size.

"About half a year ago, I and one of the leaders of this research, Prof. Andrew Dzurak, were asked when we expect a single-atom transistor to be fabricated. We looked at each other, smiled, and said that we have already done that," says Dr. Mikko Möttönen. "In fact, our purpose was not to build the tiniest transistor for a classical computer, but a quantum bit which would be the heart of a quantum computer that is being developed worldwide," he continues.

more:

http://www.sciencedaily.com/releases/2009/12/091206085833.htm


(a) Colored scanning electron microscope image of the measured device. Aluminum top gate is used to induce a two-dimensional electron layer at the silicon-silicon oxide interface below the metallization. The barrier gate is partially below the top gate and depletes the electron layer in the vicinity of the phosphorus donors (the red spheres added to the original image). The barrier gate can also be used to control the conductivity of the device. All the barrier gates in the figure form their own individual transistors. (b) Measured differential conductance through the device at 4 Tesla magnetic field. The red and the yellow spheres illustrate the spin-down and -up states of a donor electron which induce the lines of high conductivity clearly visible in the figure. (Credit: American Chemical Society)

[cliffordu]

1. Dayum.

[valerief]

2. Stuff like this just blows my mind! Of course, I don't have too many electrons in my head, but

this is still WAY COOL!

:applause:

[Occulus]

11. You have a TON of electrons in your head, actually

:)

[valerief]

12. Yeah, I know. Just a shot at self-deprecation. I'm no scientist, but I know cool when I see it!. nt

[Botany]

3. Well I built this

[valerief]

13. I'm getting vertigo just thinking about riding it!

:rofl:

[hootinholler]

4. Holy Fuck Me Harder!

This is HUGH! er, TINY!

-Hoot

[Gregorian]

5. The qubit! Unbelievable.

And I was talking to my father over the holiday about his time at Beckman Instruments where he could wander in and out of Shockley's office. An office full of engineers some of whom started places like Intel. It's hard to believe it's still going on. This is really quite remarkably similar to the diode junction discovery.

I am wondering what the applications could be. Programmable robots that run around the organs of the body repairing it.

[qazplm]

9. Honestly, I think that IS something we will see

in 30 or 40 years.

I'm really beginning to believe that if not folks my age (39) then folks right after me, could see lifespans of 200-300 years because of our increasing ability in the near future to fix errors at a cellular level. Combine gene therapy with small machines going in and tweaking this and adjusting that with stem cells to grow replacement organs of your own tissue to bionic advancements to cancer and disease research and traumatic accident would seem to be the futures number one cause of death, not old age or disease.

I wouldn't expect to necessarily see 120 year olds looking like 30 year olds but you might see them looking like 50 year olds for a long period as technology keeps up just enough to keep them roughly around that area.

Obviously a problem for overpopulation but it could also provide a burst in other areas that might advance society in ways we haven't thought of or can't think of. Imagine a 200 year lifespan. You could have periods of learning and work, learning and work, putting in several careers over your life, not limited to picking just one.

I know I will die one day, probably in the next 40 years...but there is the tiniest of chances, just the tiniest but there, that I might be blessed with another 40 or 60 or even 100 years after that. That would be awesome because death is going to have to drag me out kicking and screaming!

[phasma ex machina]

10. From my experience, Given Imaging's capsule endoscopy comes the closest to Asimov's

"Fantastic Voyage." It takes days for a capsule to pass through a patient's GI tract, which forces the rendering physician to fast forward through the recording.

[TheMadMonk]

14. Holly. Give me Rimmer's light bee. nt.

[sakabatou]

6. Now, to put it in use

How much better will out computers be?

[caraher]

7. good work, but don't get too excited

in terms of miniaturization existing transistors have a far greater density than the device shown here. (Yes, the qubit is a single atom, but if you look at the SEM photo the structure required to maintain and address the qubit is on the order of a micron in size.)

As the article suggests, this is a great test bed for examining the ultimate extreme of miniaturization and a possible path to scalable quantum computing. But for years to come the standard computer will remain far ahead of this technology for most practical use.

[kentauros]

15. I'm not too excited either, as the first thing to come to mind was "atom drift"

or Electromigration ;)

per Wikipedia:

Electromigration is the transport of material caused by the gradual movement of the ions in a conductor due to the momentum transfer between conducting electrons and diffusing metal atoms. The effect is important in applications where high direct current densities are used, such as in microelectronics and related structures. As the structure size in electronics such as integrated circuits (ICs) decreases, the practical significance of this effect increases.

I wonder how often that single atom "pops out of joint" when too much current is applied, or too quickly...

[DavidDvorkin]

8. Odd that Sciencedaily says it was "discovered"

Rather than "created".