This is just a short update to include a link to the solver code developed by Matthias Troyer et al. that I discussed in my last blog post.
The advantage of conventional open source code is that everybody can play with it. To the extent that the code faithfully emulates quantum annealing of an Ising spin model, this will be a net benefit to D-Wave as it allows programmers to perform early testing of algorithmic concepts for their machine (similar to the emulator that is part of D-Wave’s evolving coding environment).
Matthias Troyer attached the source code to this earlier paper, and for easier download I put it into this zip file. As I am hard pressed for time these days, I didn’t get to work with it yet, but I confirmed that it compiles on my OS X machine (“make an_ss_ge_fi” produced a proper executable).
Meanwhile D-Wave continues to receive good press (h/t web 238) as the evidence for substantial quantum effects (entanglement and tunneling) keep mounting, indicating that they can successfully keep decoherence at bay. (This older post on their corporate blog gives an excellent introduction to decoherence, illustrating how thermal noise gets in the way of quantum annealing).
On the other hand, despite enormous theoretical efforts, it is yet not decisively shown what quantum resources are required for the elusive quantum speed-up, but this recent paper in Nature (arxiv link) claims to have made some substantial headway in isolating some of the necessary ingredients (h/t Theo).
While this is all quite fascinating in the academic sense, at this time I nevertheless regard quantum speed-up as overrated from a practical point of view. Once I manage to set some time aside I will try to explain in my next blog post why I don’t think that this has any bearing on D-Wave’s value proposition. There’s no place in the multiverse for the snarky, dark movie script that Robert Tucci offered up the other day 🙂