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Cascading Molecules Drive IBM's Smallest Computer

Posted by ryuzaki0 on from the it's-around-here-somewhere dept.

Benoit Fries writes "EE Times reports that IBM researchers have created a simple computation engine that's more than 250,000 times smaller than the most advanced silicon circuitry. Called the world's smallest computer, the system relies on a 'molecular cascade' that pushes a handful of carbon monoxide molecules across a copper surface to perform digital logic functions. 'Even if CMOS density follows Moore's Law for 40 more years, molecular cascades are still going to be smaller,' they said."

3 of 218 comments (clear)

  1. hmmm... quantum effects by lingqi · · Score: 5, Interesting

    Somebody correct me if I am getting this whole thing wrong, but AFAIK, when you go down to molecular levels, due to the uncertainty principle, sometimes the dominos will not fall as you predict, becauese either
    1) they were already fallen you just didn't know, or
    2) statistically speaking there is a much higher chance for "spontaneous reverse-thermodynamics" on a molecular level.

    what i mean is that while macroscopically speaking, the universe is headed toward higher entropy, molecularly speaking, it's not necessarily so; The example commonly given is that you can drop and shatter an egg, or an shattered egg can come together, absorbing the sound waves etc and rise back into your hand. the latter will not (or, has completely ignorable probability of) happening, but as you and the egg gets smaller, the chance of this ignorable probability becomes less so.

    hence, a molecular computer has the probability of operating "faultily" because of the laws of thermodynamics is not followed 100%. this is currently overcome by the thousands / millions of electrons we send over gates, probabilistically speaking they still behave on a macro level, but a molecular computer has no such luxury.

    i mean, even there was only a minute chance that one molecule will go backwards as what we intended -- counting up the billions of calculations per second we expect from each chip, and the number of chips out there, and then the number of seconds / days / monthes / years they are expected to operate, the chance of error is almost inevitable. some serious redundancy / self-healing hardware / software might need to be invented.

    i am just blabbing, though. like i said: i am no molecular physicist, so if there are some here, please comment.

    --

    My life in the land of the rising sun.

    1. Re:hmmm... quantum effects by Compuser · · Score: 5, Interesting

      Well, as someone doing stm research I think
      I am qualified to answer. Quantum uncertainty
      isn't THE problem in this case. You are dealing
      with huge atoms like copper and even huger
      system like CO. They aren't exactly classical
      at this scale but they aren't going to tunnel
      out either. Especially since this research was
      done at or below 4K (Don only has low temp.
      microscope in the lab). At that temperature stuff
      doesn't like to go anywhere.
      The real limitations here are:
      a. STM is slow. In this case STM is used to
      manipulate individual atoms so it will be hard to
      make this much faster than it is already.
      b. STM tips sometimes change. They are usually
      atomically sharp so the probability of one atom
      moving is not altogether small. Not a big deal
      in research but may not be reliable enough for
      production.
      c. Copper or any other surface cannot be made
      entirely free of defects. This limits the size of
      circuits you can build. I will be amazed if this
      technology scales at all (even by one order of
      magnitude).
      d. Did I mention this will only work so reliably
      at low temperature? You have heard of crazy guys
      cooling their OC'ed rigs with liquid nitrogen...
      Well, this is waaaay colder than that.

      All that said, this is very impressive work as far
      as research goes.

  2. Re:Think Smarter - new IBM motto by bmwm3nut · · Score: 5, Interesting

    actually smaller and slower is fine. i read a great article by richard feynman (i believe it's in the 'feynman lectures on computing' series). where he was talking about the theromodynamics of computation. if we slow down the computers and use much less voltage then we can get away with using a lot less power. with the added savings in power we can use more processors in parallel. it turns out that the way everything scales, you get more speed out of parallel processors and use less power. i don't remember all the arguements, it's been a couple of years since i read it, but if you find the book it's definately worth reading.