[ExI] Quantum computer advance

Kelly Anderson kellycoinguy at gmail.com
Wed Feb 22 19:49:00 UTC 2012


2012/2/20 John Grigg <possiblepaths2050 at gmail.com>:
> And so is this really a gigantic scientific leap forward in terms
> of functional computational power?  And when will we see it seriously put
> into use?

I'm guessing around 2020.. :-)  Right when Moore's Law says it should
be available... LOL.

It is a little hard to say from the video how small the overall
transistor would be. Yes, the one atom forms the transistor, however,
the physics of the leads going up to the atom appear to be a fair bit
larger. They have managed to replace a single atom in a silicon
"diamond" with phosphorous, which is cool, but a functional transistor
would be quite a bit larger than the phosphorous atom because of the
leads that carry the electrical current up to the phosphorous atom. In
the video, the space between the leads and the atom was on the order
of ten spaces of the silicon diamond grid. So, they are at least an
order of magnitude bigger than an atom to implement the actual
circuit.

The next step is for them to create a bunch of these in a grid and see
how far apart they have to be to maintain their transistor behavior.
That's the real size, not the size of the phosphorous atom.

Now it should be fairly obvious to most on this list... but in case
someone is new, I'll explain the simple nature of the problem... The
speed of light is the approximate speed limit of the universe
(neutrinos pending) and electricity travels in a wire at a good
percent of the speed of light an no faster. So, by building
transistors smaller you get a faster CPU. Since it is 2 dimensional,
halving the size of the overall transistor and circuit leads to a 4x
improvement in speed. So the trick is building lots of transistors
close together to make it smaller. Of course if you could go to 3D
transistors, then every time you cut the size in half you get an 8
fold increase in processing speed. Nobody has done this yet because
conducting heat out of the way becomes very difficult in 3d chips.

The real breakthrough I'm hoping for is a transistor that works
without emitting heat. If we can do that, then you can start making 3d
chips, and that will keep Moore happy for quite some time to come.

Nevertheless, this is seriously interesting stuff, and smaller
transistors are absolutely a great thing to build, and you can't get
much smaller than this, it would seem... but you could potentially go
3D with something like this and build something truly amazing. Silicon
"diamonds" are a nice 3D substrate.

I also don't see exactly how this is quantum computing...

-Kelly



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