It seems that they did build a probably quantum but quite likely not computer. They are actually solving some optimization problem. And they do this quite well. However as far as I understood, they did not convincingly demonstrate that they are actually using a quantum version or a classical version of the system. And quite likely they can not run arbitrary computations. So it seems that the jury is still out, if they did build a quantum computer or a very specialized classical hardware.
There have been some calculations that are consistent with entaglement which is a premise for quantum behavior.
However D-Wave isn't a general quantum computer. It's an adiabatic quantum computer. I'm pretty sure it can't solve Shor's algorithm, because it only does function optimizations.
This is absurd. That's a comment on a blog post, proposing a bombastic title, "Better than Shor". I'm pretty sure if they could get anywhere near Shor using their architecture they'd get more than a sympathy Nature paper.
The truth is, D-Wave has done nothing to foster the coherence of their "qubits", and so they have built a very expensive, superconducting, classical computer. There is no quantum trick, actually. You have a system of buckets and you adjust the pipes and pumps between them so that in steady-state the water levels solve some problem you program in (with the pumps). Then you start in a random configuration, turn on the earthquake machine for a bit of randomness, and end up in the "ground state" solution.
The exponential speedup of quantum algorithms is sketchy enough: good luck performing an N-qubit logic gate, or in assuming that it's your favorite black-box that need only be executed a polynomial number of times (every quantum computing textbook uses their own set of universal gates). But these guys aren't even trying.
The truth is, D-Wave has done nothing to foster the coherence of their "qubits", and so they have built a very expensive, superconducting, classical computer. There is no quantum trick, actually.
Scott Aaronson, the self-described "Chief D-Wave Skeptic", disagrees with you:
Now, I’d say, D-Wave finally has cleared the evidence-for-entanglement bar—and, while they’re not the first to do so with superconducting qubits, they’re certainly the first to do so with so many superconducting qubits. So I congratulate D-Wave on this accomplishment. If this had been advertised from the start as a scientific research project—”of course we’re a long way from QC being practical— —but we’ve shown experimentally that can entangle 100 superconducting qubits with controllable couplings”—my reaction would’ve been, “cool!” -- http://www.scottaaronson.com/blog/?p=1400
If they actually do have a factoring algorithm, it's easy for them to prove: factor something we give them that is obviously unfeasible for classical computers and give us the result.
Quantum computers can't solve arbitrarily large factirisation problems. The signal gets weaker the largers the numbers get to the point where factoring a 4096 bit number is not going to happen.
Real quantum computers don't exist. If one did exist it would need to factor numbers much larger than 4096 bits efficiently for it to be considered a real quantum computer.
And all true scotsman wear kilts. We consider 8bit computers real computers even though they can't run windows 8. The same can be said for quantum computers, a 64qubit quibit quantum CPU could be vary useful even if it can't factor 4096bit numbers.
PS: We have solid state 4bit quantum computers right now. They may not be useful for much, but that's in part because we have spent hundreds of billions of dollars perfecting classical computers.
Like you, I was worried about the snake oil aspects of qc, but ...well, I got over it when I looked into the science of the d-wave implementation and talked with folks like Sergio.
Please note,we're talking about a quantum annealer here, not a full on qc and we're okay with that :-) Also, disclaimer: I'm a googler who worked with our quantum folks and nasa to get the machine in place.
Not that I know of, but my most recent information comes from this over-a-year-old post: http://www.scottaaronson.com/blog/?p=954 Google buying one doesn't make me shift much one way or another -- D-Wave has built something interesting that seems to be faster than other hardware, they are able to improve from the marketing buzz around 'quantum', but may or may not be using any quantum effects. People like http://jeffjonas.typepad.com/ have algorithms for problems that do increasingly better than the competition with increasingly "harder" or larger instances, so that behavior isn't really that weird.
It is unclear if they are actually taking advantage or quantum effects or if similar machines could be built using much simpler and cheaper classical effects.
