…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.