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Science Technology

Aussie, Finnish Researchers Create a Single-Atom Transistor 96

Posted by timothy
from the for-small-transitions dept.
ACKyushu writes "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 comprises only a single phosphorus atom in silicon. The results have just been published in Nano Letters. 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."
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Aussie, Finnish Researchers Create a Single-Atom Transistor

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  • by Anonymous Coward

    Intel already has Atom processors.

    • by toriver (11308)

      ... and the Acorn Atom predates both.

      • The Hydrogen and Helium atoms, predate all 3... by a fair bit. Though I imagine it is our of patent/copyright by now unless the US laws get realllllly screwed up in the near future.
  • Perhaps I can reach over 9000 Ghz ...
  • Big Deal (Score:5, Funny)

    by Karpe (1147) on Sunday December 06, 2009 @07:16AM (#30342374) Homepage

    We've had single Atom CPUs for some years now... :)

    • by celle (906675)

      "We've had single Atom CPUs for some years now... :)"

      Now if we'd just stop electing the bastards...

  • Cosmic rays (Score:3, Interesting)

    by Alain Williams (2972) <addw@phcomp.co.uk> on Sunday December 06, 2009 @07:47AM (#30342474) Homepage
    If the state of a gate depends on one electron, it will be highly sensitive to radiation. So what do we do ? Embed these in large blocks of lead ?
  • by Anonymous Coward

    ...Wouldn't that be kinda hard to read?

  • by Anonymous Coward
    Do people really need to be told where Helsinki, New South Wales, and Melbourne are?
  • by Ancient_Hacker (751168) on Sunday December 06, 2009 @08:42AM (#30342638)

    This thingy is just a research device, just good for research. It's not a precursor of anything practical.

    It's been known for many, many years that there are serious tradeoffs to be pondered when you shrink transistors (and FETs).

    Your basic linear dimension versus surface area versus volume scaling laws are in full play here.

    You win at first, as smaller base or gate lengths lead to more speed, and less surface area means less capacitance to charge up.

    But below a certain size the rapidly shrinking cross-sectional area reaches its current-carrying capability, while noise and leakage loom large.

    Right now the low-level chip designers, with their 10^12 atom transistors are already spending a large part of their time with these issues. The challenges are not going to go away, they just get larger as one attempts to shrink things even more. It's unlikely that these hard challenges can be overcome to span the million-million times distance to a true one-atom transistor.

      So don't put any big money on ever having one-atom transistors in any practical device.

    • This is without mentioning that the potential for this one-atom setup to have a severely reduced usable lifespan has to be through the roof. How much force can it really take to displace one damned atom? What happens when heat and time stress everything it's connected to?

    • Re: (Score:3, Interesting)

      by mangu (126918)

      So don't put any big money on ever having one-atom transistors in any practical device.

      I'm old enough to remember when people said no dynamic memory chip could ever be made with more than 64 kilobits capacity. The capacitor charge would be flipped by radiation hitting the chip [wikipedia.org].

      Probably this is the origin of the "640 kbytes should be enough for anybody" meme, since, with 64 kbit chips, it would be difficult to pack more than the 80 chips needed for 640 kbytes in a desktop computer.

      • by Rexdude (747457)

        The 640k quote was relevant in 1981, when it seemed like a lot. It also was due to a limitation of the 8086 CPU's 20 bit address bus.Here's [si.edu] an excerpt from a 1993 interview where Gates clarifies his quote.

        In real mode, the 8086 can only address 1 MB of RAM, out of which 384KB is reserved for video RAM. Hence the 640k restriction on memory (640=1024-384).
        Using extended [wikipedia.org] and expanded [wikipedia.org] memory managers, it was possible for DOS programs on the 286 and higher CPUs to access memory beyond 1 MB by mapping it into pag

    • Apart from the implications this might have for classical electronics, the long-term goal here is to build solid-state quantum computing devices. The phosphorus donor has one lonely electron, and that electron's spin is a good candidate for a qubit. One of the good things about P in Si is the long decoherence times -- T2 times of almost one second have been demonstrated. The phosphorus' nuclear spin of 1/2 stays coherent for hours, if we can find a way to get at it.

      Of course, the NIST guys with their ion tr

    • million-million

      Is that the retard way of saying “trillion”?
      Or do you think we are retards?

      Or did you just not want to remind us of Zooey Deschanel [google.com]? :P
      I like to be reminded of her, you insensitive clod!

      Oh well, the “Jesus” in the subject already gave it away anyway, who’s not right in his head. ^^

  • by tomhath (637240) on Sunday December 06, 2009 @10:08AM (#30342948)
    Would be designed around a Higgs Boson which would know when to come back from the future and switch with no gate delay...
  • by rossdee (243626)

    The active part is a single atom of Phosphorus ? While it might sound like you could get high density circuits with that, I hope they plan on using water cooling, given that phosphorus tends so spontaneously combust.

    • Re: (Score:3, Informative)

      by HiThere (15173)

      FWIW, phosphorous will burn water. It pulls the oxygen away from the hydrogen. So in my high school chem lab it was stored under kerosene instead. Quite mind boggling at the time.

      So if you're going to worry about spontaneous combustion, perhaps you should cool your computer with kerosene rather than water.

      • by Amanitin (1603983)

        This is not true. You can extinguish burning (white) phosphorus with water. Trouble is, after the water runs off it will self ignite again on contact with air above 30 degrees C.
        Its this one allotrope out of many that is highly reactive, and single atoms embedded in silicon have hardly anything to do with the character of a bulk of the pure element.

      • And then presumably store it in a noble gas atmosphere...
  • Because SMDs aren't tedious enough already...

  • Just one atom in millions. Magic!
  • "The results have just been published in Nano Letters."

    I'm guessing that'd be a Times New Roman 0.0000001 pt font then? Damn, I left my scanning electron reading glasses at home today.

  • Published in nano letters? I don't have an electron microscope, you insensitive clod!

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