

Quantum Computer is 10^80 faster than a conventional computer - willvarfar
http://sydney.edu.au/news/84.html?newsstoryid=9081

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almost
10^80 faster at _what_?

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drostie
At simulating the quantum mechanics of simple 2D spin systems, from what I
gather from the Nature article.

The press release sounds like they've developed a quantum computer, but this
is not borne out by that article. While there is lots of promising work in
quantum computing as a whole, this as I understand it can't be used for that,
because you can't tune the qubit interactions individually but you can only
tell the whole lot to do the same thing. (At least, the abstract doesn't seem
to discuss anything more complicated than giving them all a ferromagnetic or
antiferromagnetic coupling.)

If that's correct, then this article seems overstated. At the very least, I
know there are now "optical lattices" of qubits made from atoms supercooled
into a Bose-Einstein condensate and then relaxed into a very pure square
lattice. You don't have to know what that means, just know that with some
method which is now reasonably well known, you can get much much more than 300
atoms interacting via quantum mechanics. Like, optical lattices get hundreds
of thousands, if my memory serves me correctly. So this isn't, like, the
biggest entangled system ever demonstrated of this form -- not by far. It
_might_ be the biggest which has this level of tunable Ising interaction, that
I don't know. But there are now tons of approaches to quantum computing, and
yes, some of them can throw much larger numbers at the problem than just 300.

The very nice thing here seems to be the quantum entanglements getting done
over a spacing of 30 microns. That might not mean much to you, but the optical
lattice work is done at tiny spacings, and it becomes extremely difficult to
do any sort of individual readout. 30 microns means that you have a lot of
leverage to address individual atoms. If you could get them all to entangle
with each other and then you could manipulate them individually with some
gates, you might be able to get some good quantum error correction set up.

That probably also doesn't mean anything to you. The important fact about
quantum error correction is this: once your QEC is reliably set up, you have
passed the critical barrier and you can scale up arbitrarily to a quantum
computer by just throwing more atoms at the problem.

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yvdriess
It sounds like this bodes well for measurement-based (aka one-way) quantum
computers. a) We can make a massive amount of entangled qubits and b) each can
be manipulated and measured separately.

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Lewton
Holy fluff piece batman!

Sure is a lot of text with almost no detail

Edit. Ah, there's more info in the video

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mrsebastian
Not much, though -- seems like he's basically paraphrasing the press release
:(

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tzaman
I want one of these in/as my GPU.

