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Comment by eghad | Hacker News Reader

The UCSB professor you're referring to is John Martinis [0] and though the physical structure differs (they're using small arrays of "Xmons" instead of typical transmons qubits to minimize decoherence and thus error) they're still working within the realm of adiabatic quantum computing/quantum annealing, the same general avenue D-Wave is pursuing (with a "digital" twist) which is why Google invested in both of them.

[0] http://web.physics.ucsb.edu/~martinisgroup/publications.shtm... [1] https://research.googleblog.com/2016/06/quantum-annealing-wi...

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Sorry that's just not correct (to my knowledge at least), as John was always working on gate-based quantum computing and is currently pursuing designs based on resonator-coupled Transmon qubits (the X-mon refers to the geometry of the qubits, which provide four capacitive ports to couple them to resonators and fast flux lines). The next milestone for their collaboration is the demonstration of "quantum superiority" using a 40(-ish) qubit processor to perform an algorithm that is beyond the reach of current supercomputers. The real effort comes afterwards though as the system needs to be scaled up in order to be useful in any real-world task.

The quantum annealing example from the Google research blog seems to use normal quantum gates to simulate the nearest-neighbor interactions in a spin chain. The nature article is currently down but it seems they use "Trotterization" to simulate the spin chain using one- and two-qubits gates.

It is indeed, correct. The annealing example I linked is from his team (here's another one with full citation with Martinis at the end there [0]). And if you want further proof that Martinis and the Google Quantum team are pursing quantum annealing look no further than the Adiabtic Quantum Computing Conference that was held this summer where their team held several talks including "Building Quantum Annealer v2.0" [1].

And I didn't touch on your earlier (erroneous) comment on the scientific community's perception of D-Wave, but I think it needs to be said that in actual professional circles the research they're performing isn't met with as much derision as they seem to garner in these more causally informed settings. It's hyped and a difficult subject to understand, so that's fair, but I suggest really informing yourself if you're going to go out there and make the claims you're making.

[0] http://research.google.com/pubs/pub44292.html [1] https://aqccreg2016.eventfarm.com/events/index/7fff5387-0000... http://1qbit.com/insights-inside-googles-annual-adiabatic-qu... [2] (Another article reviewing QA with Martinis and team) http://arxiv.org/abs/1512.02206

I actually did my PhD on superconducting quantum computing with Transmon qubits, so I really wouldn't say that I'm only "casually informed" about the subject.

Again, their digital adiabatic quantum computing relies on a gate-based quantum processor, which provides a universal set of qubits gates and thus can in principle simulate any Hamiltonian, quantum annealing is just an algorithm that runs on it.

And I don't want to be overly negative, but the perception of D-Wave in "more professional" circles was not very enthusiastic in my experience, which to a large extent is also D-Waves fault.

[...]in actual professional circles the research they're performing isn't met with as much derision[...]

Yes it is.

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