Cascading Molecules Drive IBM's Smallest Computer

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."

Comments

Think Smarter - new IBM motto

[Dark Coder]

I think IBM is going off the wrong direction in tackling Moore's Law.

We should be attempting massive parallelism instead of packing more logic per area.

Isn't that how our brain works?

Re:Think Smarter - new IBM motto

[bmwm3nut]

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.

Computing model

[fleppir]

Niiice. This means we don't have to learn new calculus to program assembly and STILL experience the computing power of single atoms. Good. My head hurts when thinking about sets AND super-sets at the same time (read, quantum computing)

Re:CO in this application will be safe

[Pig Hogger]

(Interesting side note: CO asphyxiates you by binding very tightly to the iron in hemoglobin in your blood, much more tightly than oxygen can. IIRC, however, CO will preferentially bind to copper over Fe.)

So this is why octopuses (octopii???) are very sensitive to outboard-engine exhaust: their blood doesn't have hemoglobine, but the copper-based equivalent.

hmmm... quantum effects

[lingqi]

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.

Re:hmmm... quantum effects

[shirameroix]

In the article it was said that 10,000 hops were executed, and in that time, no noticeable errors were seen. Call me crazy, but thats a lot of hops and no error to speak of. I thought it was also interesting how IBM said that the tests were performed at 4k. I dont know about you, but molecules move pretty freakin slow at that temperature. Like the article said, boost the temp, and the speed of the circuit should increase as well. This may not be as slow is the EE times article made it out to be.

Re:hmmm... quantum effects

[Compuser]

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.

Re:Just what we need!

[joto]

Yes, a few billion CO molecules are really going to kill you. In this test, it was probably more in the range of hundreds. A gram of CO is about 21499952344431130617588 molecules. I think you should be more worried about the stuff in current computers...