By the end of 2017, Google hopes to prove quantum computers can beat classical | Hacker News Reader

By the end of 2017, Google hopes to prove quantum computers can beat classical

spectrum.ieee.org

83 pointsfrostmatthew37 comments

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.

Here's an educational video on the subject that explains it in a way that everyone can understand. https://www.youtube.com/watch?v=JhHMJCUmq28

This video doesn't discuss quantum supremacy, so it does nothing to answer his question.

It does however establish the background material. Inability to make the connection is a failure of intellect and imagination.

It wasn't clear to me either. Demonstrated "supremacy" over conventional general-purpose CPUs, as described in the article, does certainly read like hyperbole.

"Supremacy" is a technical term used by people in the field, albeit sometimes in different ways.

https://twitter.com/quantum_graeme/status/849317195599556609

Interesting, I assumed they meant the term colloquially.

Here is another link that, while being a tiny bit mathematically rigourous, made me have an "a ha" moment about how quantum computtattion works.

PBS Digital Studios is truly a treasure and really shows what's possible with eduxation when you truly take advantage of internet video.

You mentioned a link to another educational video, however; you provided no links in your comment. Would you mind editing your content to include the link? I'm quite interested.

Maybe this video? https://www.youtube.com/watch?v=IrbJYsep45E

You also read my mind.

I tried to find it im the PBS Digital Studios YouTube channel and failed. But I did learn about PBS Digital Studios!

Specifically, it's the Infinite series. Math is so much easier to understand with animations. Something that would take me hours of dense reading of some dusty tome can to grok requires only 20 minutes with modern video production

Also, I'm glad you became a fan! Some people mock anything that is government funded and reflexively assume private enterprise always makes a superior product.

One exception of many to this I recently found is when the gf and I were watching tv and she changed the station to the Science Channel. My excitement was destroyed by my exponentially higher dissapointment: The tv show she wanted to watch was Ghost Hunters...on the frickin science channel!!!!

Some people mock anything that is government funded and reflexively assume private enterprise always makes a superior product.

I am grateful to have never knowingly met one of these people.

Perhaps this is it?

https://www.youtube.com/watch?v=IrbJYsep45E

It is indeed

I hate posting from my phone. Here it is:

https://www.youtube.com/watch?v=IrbJYsep45E

I don't know a good link to a discussion of this system, but the idea of establishing quantum supremacy has been much discussed in optical systems under the title of boson sampling.

https://en.wikipedia.org/wiki/Boson_sampling

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

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.

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.

If you'd checked the article, you would see that actually he's solidly in favor.

But yes, it's basically "represent a quantum computer of this size", which we legitimately can't do classically beyond a certain size. It's not hugely useful but it's legitimate quantum supremacy, if it works.

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.

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

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.

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

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.

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.

Oh you heard it talked about on a podcast? Well, then, all bets are out.

It is ridiculous the extent to which laymen commenters feel they don't need to understand more in order to even have a chance of mattering in a conversation.

Well I'm reporting what I heard. Feel free to ignore it.

> _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?

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

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.

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

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.

Yeah we had a typo in there—sorry.

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