Single-atom transistor developed

2012-02-19 22:17

Paris - Researchers in Australia said on Sunday they had made with pinpoint accuracy a working transistor consisting of a single atom, marking a major stride towards next-generation computing.

The device comprises a single phosphorus atom, etched into a silicon bed, with "gates" to control electrical flow and metallic contacts that are also on the atomic scale.

"Our group has proved that it is really possible to position one phosphorus atom in a silicon environment, exactly as we need it, with near-atomic precision, and at the same time (incorporate) gates," said lead scientist Martin Fuechsle.

Transistors, which switch or amplify electrical flow, are the building blocks of computer chips.

For more than 50 years, the semi-conductor industry has been upholding Moore's Law, the celebrated prediction by Intel pioneer Gordon Moore that the number of transistors on a chip would double every 18 months or so.

But the astonishing run of success could hit a wall by the end of this decade without a breakthrough in miniaturising transistors.

The team made the transistor from a silicon crystal that was placed in a vacuum.

To etch it, they used a device called a scanning tunnelling microscope, which is able to see atoms and manipulate them using a super-fine metal tip.


Phosphorus atoms were deposited in a nano-scale "trench," covered with an inert layer of hydrogen, and the unwanted ones were then weeded out. A chemical reaction welded the "transistor" atom to the silicon surface.

The minute device operates in ultra-cold temperatures provided by liquid helium.

It is not a finished product but proof-of-principle, designed to show that single-atom devices can be built and controlled.

Scientist have made atomic-scale transistors in the past, but through a chance find rather than by design, said Michelle Simmons, director of the Centre for Quantum Computation and Communication at the University of New South Wales, where the work was carried out.

"But this device is perfect," she said.

"This is the first time anyone has shown control of a single atom in a substrate [chip base] with this level of precise accuracy."

The research is reported in the specialist journal Nature Nanotechnology.

  • Oneant - 2012-02-19 23:18

    wow.. the University of New South Wales has a Centre for Quantum Computation and Communication... What does South Africa have that is comparable? Hmmm... nothing. Why? Well... im sure the forum can provide the answer.

      Tinus - 2012-02-20 08:04

      wow.... South African invented Pratley putty has been used on the moon!!! What does Australia have that has been used on the moon....Hmmmmm...nothing. Why? sure an Astralian will provide the answer.... If you really want, I can go on for hours mentioning stuff. So what is your point actually????

      ralph.schminke - 2012-02-20 08:14

      What exactly did your comment contribute towards ... What was the gist of your comment .. To see how bad S.A. is ??? Do you even know what research is being done is S.A. universities? If you still live in S.A. , leave please - or if you have emigrated already like the mindless hoard who have preceded you , good riddance.

      Tinus - 2012-02-20 10:09

      This is a lame attempt to discredit the South African scientific fraternity’s application to host the SKA. Try to be more imaginative in future.

      kenneth.mthethwa - 2012-02-20 10:12

      Just leave Mzanzi 1 ant.

      barabus2012 - 2012-02-20 11:25

      @Oneant - As much as i like bashing this goverment, i must say you've gone the extra mile to fish for a fight. Whether it applies now, SA engineers were at the forefront of major technologies. The USA has had some of its military technology built and designed here in SA. I could probably sit here for another hour or so to list the wonders that have come out of this great nation. It may not be the case today, but we cant look for any excuse to bash this goverment (although i thouroughly enjoy doing so)

      Nigel - 2012-02-20 11:38

      Oneant, you are trying to say what????????

  • Marumo - 2012-02-20 01:34

    We do have scientists who work on quantum computing at UKZN. The issue here is that the Australians found the material that can be manipulated to form the basis for transistors of today. This is still a proof of concept not a product yet.

      Suki - 2012-02-20 02:54

      Research institutions are suppose to develop "proof of concepts", not products - that's left to industry. Further, a research group is considered amateurs unless they publish in reputable journals and makes significant discoveries as mentioned in the article. I doubt UKZN has enough resources to be considered serious contenders.

      npretorius2 - 2012-02-20 09:47

      most of UKZN's "recources" are at home waiting for brand name condoms, the rest are burning down campusses...

  • Nikki - 2012-02-20 07:17

    Love how this article starts: "Paris - Researchers in Australia..." Huh?

      Clive.D.Buckley - 2012-02-20 10:35

      this is because the article comes from AFP (Agence France-Presse) which is a French News agency...

  • David - 2012-02-20 08:21

    Science Fiction is soon to become science fact!

      Brett - 2012-02-20 12:02

      It has happened and continues to happen every day, David. The last century was very exciting and we're hurtling forward at exponential rates. This morning's science fiction will be this afternoon's science fact! Cue all the Singularity protagonists ;)

      Retardus - 2012-02-20 13:47

      @Brett Singularity Protagonists NICE !! Haven't thought about that in years.

  • bernard.gerretsen - 2012-02-20 11:06

    agreed with ralph and kenneth, please leave SA 1 ant. lots of decent people trying to make a go at it here in SA can do without your negativity. everytime another country achieves something does it have to be compared to SA? maybe they can design an atom sized douche bag for 1 ant?

  • Brian - 2012-02-23 22:33

    "Researchers in Australia said on Sunday they had made with pinpoint accuracy a working transistor consisting of a single atom" Pinpoint Accuracy is a bit of an understatement don't you think?

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