Interview with MIT Technology Review magazine

…can be found here. A version of this article is to appear in the April 8th issue of the New York Times, which is absolutely great.

Articles about contentious issues, with people seeming to take opposite sides of something that sounds important, get a lot more readers than ones where everyone agrees about something. In that spirit I would like to make a few comments directed at the folks who are being portrayed as being somehow opposed to our effort or its objectives (like Scott Aaronson, Umesh Vazirani, etc.).

Let me start be quoting a passage from the TR article.

Of Geordie Rose’s claims to having built the first practical quantum computer, Aaronson wrote in an e-mail, “Whatever else D-Wave might or might not have done, this can be instantly rejected as hype. If by ‘practical’ he means able to solve practical problems faster than existing classical computers, then this is clearly false. If he means able to solve tiny demonstration problems, he’s been beaten by loads of people. So I can’t think of any interpretation under which he’s telling the truth.”

It’s my view that we have built the first practical quantum computer, so let me present an argument in support. Let’s say Scott, as an intelligent non-expert (in experimental physics), wanted to run a program on a real quantum computer, and for the sake of specificity let’s compare a liquid state NMR QC vs. Orion, without any outside help except for any documentation he could find. The problems associated with converting an algorithm to an actual NMR QC pulse sequence that does what you want are Significant. In fact we enlisted the help of one of the world-leading NMR QC groups a couple of years ago to run a small molecular simulation algorithm, which failed because of the complexity of the pulse sequence required (including refocusing, etc.). Now if Scott wanted to solve a Maximum Independent Set problem on Orion, here is what he has to do: (1) load a graph into a database program; (2) type Find MIS in graph; (3) voila the output arrives on his terminal. He can do that from his couch at home, as long as he has an internet connection.

So if by practical I mean “concerned with actual use or practice” , which I believe is an accepted definition of the word, Orion is practical (a non-expert can use it) whereas all other QCs are not (only experts have a chance of being able to use them). Ergo the world’s first practical QC.

If anybody thinks this is an unreasonable argument I’d like to hear why–seems good to me!

Here’s another quote from the article:

Umesh Vazirani, a professor of computer science at the University of California, Berkeley, said, “D-Wave is misleading the public by calling their device ‘a practical quantum computer.’ The whole point of quantum computing is achieving a large speedup over classical computers, something that D-Wave hasn’t accomplished.”

Re. the first point, either Umesh is wrong or my argument presented in the prior segment is wrong. Re. the second: This is obviously the objective of building real QCs. On this point I agree. (although I would mention as an aside that there are many other “points” to QC, and this may not even be a majority opinion). However it seems pretty clear to me that on the path to achieving this objective, an effort will create machines that are–under the actual accepted definition of what a QC is (see eg. wikipedia)–real QCs that aren’t sufficiently powerful to have reached this end goal. Like Orion.

Describing what we are doing along the way has clear benefits in two related dimensions: (1) it helps us find matches with potential users, in order to focus development on high-value applications; (2) it allows the project to be properly financed. As Umesh knows from his experience in start-ups and industry, the main failure mechanism for any start-up is under capitalization.

More on this later!

13 thoughts on “Interview with MIT Technology Review magazine

  1. I don’t think even by your definition of practical you’ll win the argument since MIT undergrads have been performing quantum computations for years in their lab class. I mean I even know theorist who have carried out practical quantum computations.

    Plus I don’t think you get to call anything practical that need to be cooled milliKelvin. 🙂

    Of course the real question is not whether it’s practical but whether it is useful. Practical is a silly and useless word.

  2. Dave: Anyone who has ever used a database can learn to use Orion in ten minutes. Surely there is a difference between that and an NMR QC, which at the very least you’d need an undergraduate degree in physics to even understand (let alone use)? Have you ever tried to create a pulse sequence for one of these things?

    Contrary to popular opinion, mK temperatures aren’t a barrier to widespread deployment. Closed-cycle (no cryogen replenishment) mK fridges exist that you just plug into a wall socket, that will take you down to 15mK.

    Re: “practical is a silly and useless word”: was that supposed to be funny (ie. world view of a theorist)? Being useful is necessary but not sufficient. A machine that is useful, but impossible for normal people to use, will fail in the marketplace. Technology is about alot more than just being useful.

  3. If conventional computer can give aproximate answer, than who needed quantum computer? What is diferent between aproximate answer given by conventional computer and aproximate answer given by quantum computer?

  4. surname: Now that is a great question.

    Two possible answers:

    1. Both get the same quality of answer (ie same level of approximation), but the QC gets it faster;

    2. In the same allotted time, the QC gets a better approximate answer.

    If either of these could be true it would be motivation to build QCs.

  5. “MIT undergrads have been performing quantum computations for years in their lab class”

    Using a physical quantum computer? or using a simulator?

  6. Shifting the discussion from the core quantum computing technology to a cute user-friendly interface is a clever move on Geordie’s part, but I am sure that the experts will see it as irrelevant. Isn’t it possible to build all the bells and whistles for the NMR computer, so that it is just as user-friendly as D-Wave’s machine? I do not see any commercial or scientific merit in a simple interface. That is the advantage over MIT’s NMR computer that Geordie claims, correct?

  7. Using a physical quantum computer? or using a simulator?

    No on an actual NMR machine.

    Have you ever tried to create a pulse sequence for one of these things?

    Nope, but if a MIT undergrad can do it, well then just about anyone can. If it were a Caltech undergrad I would be intimidated.


    Useful as in doing something computationally I care about. My coffee machine is simple, but I’m not yet ready to dedicate it towards solving protein folding experiments (though when it gets dirty maybe it is already doing some crazy biology simulations.)

  8. Geordie: Yes, but Apple has already done it and yours isn’t anything new. My point is that user interface should not be the selling point of your technology. If the MIT guys built a cool user interface for their NMR machine, what would be the advantage of D-Wave then?

  9. @Dave

    So has MIT uploaded their undergraduate quantum computing lab to their open courseware page. Because, that seems like it would be a pretty fun lab.

  10. Are we arguing over semantics again (i.e. practical)? If we are, might I offer applications-ready vs practical/useful?

    Aside: I must admit. I do find arguing semantics much more dull than actually discussing the finer points of the qc approach itself.

  11. HI Chris,

    Yes it’s boring. But semantics are the source of many of the issues with communicating new concepts. Often words have different meanings in different communities. The word “theory” comes to mind. The accident that this word means two different things to scientists and everyone else is the source of a lot of grief.

    I have found that a lot of people who have issues with our projects don’t really understand our objectives, which is a communications failure on my part.

    As atonement for this failure I must provide – daily – 10 definitions of practical, 5 definitions of solve and 3 definitions of quantum computer.

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