[Analemma_]

As far as I'm concerned, it doesn't work until Scott Aaronson says it works.

EDIT: My comment was kind of snarky and curt without much info; I need to be better about that. I did read Scott's post when it was published, and the consensus I got from it is that D-Wave's device achieves a constant-factor speedup, not a quantum one. I just think, with that being generally accepted by all parties now, it's pretty disingenuous to keep calling it a "quantum computer", when it's really a (faster) classical computer that uses quantum mechanical effects. I mean, the Intel chip in my laptop also uses QM effects because the feature size is so small, but nobody calls it a quantum computer. Maybe that's the media's fault though. Are D-Wave/Google themselves still saying "quantum computer"?

SECOND EDIT: Rereading Scott's post more carefully, it seems like Google and D-Wave are now calling it a "quantum annealing device" and are more forthcoming about the lack of quantum speedup. So unless they're talking out of both sides of their mouth and still saying "quantum computer" to the popular press to build hype, I guess everyone is a reasonable person after all and it's the media's fault as usual.

[rdtsc]

Last time I understood they got a classical speedup. And yeah if Scott says it ain't working, it ain't working, agreed there.

I am wondering if they demonstrated there is quantum entangling taking place between qubits and have they observed an asymptotic speedup?

Wonder if there is some hesitation to just say, yeah this doesn't work. We spent all this time and money on it, but that's ok. We learned what doesn't work that is still valuable.

I studied quantum computing a while back (maybe 7-8 years ago). There was a feeling it was going to be the next big thing. Grover's search and Shor's factoring was promising. But I think we ended up mostly with pictures of cats in the cloud and Javascript on the server ;-) which is ok too, I guess.

[radioactivist]

This article and the discussed work was put out last December (see http://arxiv.org/abs/1512.02206). Scott Aaronson weighed in around that time; see http://www.scottaaronson.com/blog/?p=2555.

[daveguy]

The blog entry includes a reference to the HN discussion in the updates toward the end.

The previous HN discussion clarifies that google reports a constant (although large) increase in speed for a specific application.

[themgt]

I think Aaronson's Q&A w/ MIT News is the most accessible explanation of why this isn't an "it works!" moment. It's a complex, nuanced argument so it's easier to just read than try to summarize here [1]

I think basically if you grasp why Selby's algorithm is able to beat D-Wave, you'll understand why D-Wave isn't a useful quantum computer, whatever terminology you want to use to describe it.

N.B. Even Aaronson admits D-Wave may have useful technology[2], it's just that the present "dirty qbit" approach doesn't give you a machine useful for anything more than basic science research, which is not at all how D-Wave have hyped it.

[1] http://news.mit.edu/2015/3q-scott-aaronson-google-quantum-co...

[2] http://www.scottaaronson.com/blog/?p=2555#comment-967324