
By the end of 2017, Google hopes to prove quantum computers can beat classical - frostmatthew
http://spectrum.ieee.org/computing/hardware/google-plans-to-demonstrate-the-supremacy-of-quantum-computing
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jptman
Can someone explain the computation the article talks about further? All it
says is that the array will go into a chaotic state and produce seemingly
random output.

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avz
I believe they talk about the computational task described in [1] (published
in 2016). Note that this is somewhat contrived: it's a task defined
specifically so that it is very difficult for classical computers and
relatively easy for quantum computers. It is also defined in a way that
ensures that a quantum computer necessary to demonstrate quantum supremacy is
relatively small in terms of the number of qubits.

The task is that of generating output samples from pseudo-random quantum
circuits. The paper shows that the task has exponential computational
complexity on classical computers and that it can be used to demonstrate
quantum supremacy using a quantum computer with approximately 50 qubits.

Now, the IEEE Spectrum article indicates that the team has now built a
49-qubit quantum computer and plan to use it to demonstrate quantum supremacy.

EDIT: Replaced direct pdf link with the article page link.

[1] [https://arxiv.org/abs/1608.00263](https://arxiv.org/abs/1608.00263)

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maxander
Am I right to read this as "the classical computer and quantum computer
compete at the task of _being that particular quantum computer_?" Scott
Aaronson is probably preparing to denounce this experiment already.

~~~
PeterisP
Not really "that particular", but more like performing a trick explicitly
designed to be feasible even for low-qubit quantum computers but unfeasible
even for very powerful conventional computers attempting to emulate quantum
computing.

Performing such a trick demonstrates that you have a working device that can
perform arbitrary quantum computations - unlike, say, the much hyped D-wave
quantum annealing device.

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adamnemecek
One thing that has been confusing me is why do quantum computers still work
with bits (qubits are still bits) as opposed to waves and signals. Math is
founded on continuous functions and by converting them to bits, you lose a lot
of information.

I've been toying with the idea photonic computing over the last couple of
years and I believe that a photonic analog computer is the way forward. How do
you do computation on such a computer? Dependent types -> homotopy type theory
-> topology -> topological photonics.

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platz
i heard this question raised on a podcast and my understanding is that the
gains from analog computing do not in favt yield orders of magnitude more
efficiency, so digitization is not as much of a loss as one might think

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adamnemecek
lol what podcast was this?

gains from analog computing are actually really promising, and just about
every opinion I've seen that said it wasn't was founded on some fundamental
flaw.

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dang
Would you please edit the uncivil swipes out of your comments here? Your
comment would be just fine without the snarky first three letters.

~~~
adamnemecek
That actually wasn't snarky but I see how it could be taken that way. I was
surprised that there's a podcast on this, I was legitimately curious what
podcast this was. I have very little material that deals with this, and it's
surprising that there's a podcast on this.

~~~
dang
Ah. Sorry for misreading you! But could you maybe be a little clearer in that
department? I seem to recall having a similar conversation before, and good
faith is so lossy online.

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dwringer
> _Google hopes prove ..._

I am guessing that was meant to be "hopes _to_ prove", or else we're at the
point now where for Google, merely hoping for something to be true makes it
true.

Or are we using the mechanism of "hope" to delineate between classical
computers and quantum computers, one of which we now consider Google to be?

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frostmatthew
When I submitted it I used the article's title _Google Plans to Demonstrate
the Supremacy of Quantum Computing_ , apparently one of the mods felt this was
an improvement /shrug

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dang
The HN guidelines say "please use the original title, unless it is misleading
or linkbait". This article's title is grandiose enough to count as linkbait.
In such cases, mods change titles, nearly always using either a subtitle or a
representative phrase from the article.

The reason we do this, btw, is that if we don't, the comment threads fill up
with shallow objections to the title. We don't always get it 100% right, of
course, and are pleased when readers suggest better. But the basic principle
is that, on HN, a good title is accurate, neutral, and uses the article's own
language.

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dwringer
I hope you don't consider mine a shallow objection. I rather liked the change
:)

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dang
Not at all, I meant that if the title above were still "Google Plans to
Demonstrate the Supremacy of Quantum Computing", there would be complaints
about linkbait and whatnot. Of course the complaints are usually justified on
their own terms, but they're predictable and therefore tedious, and they take
threads way off topic.

