It’s only two days until D-Wave Systems demonstrates their 16-bit ‘quantum computer’. This has stirred up quite a bit of talk recently. Although in all fairness I ought to give them the benefit of the doubt and wait until the demonstration before passing judgement, I’m not going to. In my mind, without knowing any technical details, I think it’s almost a certainty that this demonstration will be discredited. There are three main reasons for this:
1. If they do successfully demonstrate a 16-bit quantum computer, it means this small upstart company with a hand full of people will have successfully developed technology decades ahead of the entire academic community combined. I think this is quite unlikely.
2. The researchers at D-Wave, to my knowledge, have failed to demonstrate quantum coherence in their system, which rules out quantum computation.
3. D-Wave has provided no details into the working of their system. While you could argue that, being a company, this is to protect their ideas, there are plenty of details that could easily be provided that would confirm functionality without compromising their ideas. For example, quantum state or process reconstructions could easily demonstrate the existence of entanglement and quantum coherence without compromising intellectual property.
4. D-Wave repeatedly makes dubious claims about the type of problems their computers can solve, claiming they are suitable for solving NP-complete problems, which contradicts what is commonly believed by the rest of the scientific community.
In summary, I think it’s extremely unlikely that what D-Wave will demonstrate will be a quantum computer. What I think is likely is that their machine is, in effect, an analogue computer, the happens to produce the desired results in certain situations.
I’ll comment again after the demo, and once I have read more about it and actually know what I’m talking about.