With the D-Wave flavor of quantum computers, it is like solving every issue using a traveling salesman algorithm. It can be done, but you aren't using a general purpose quantum computer to do so.
Quantum computers made by Rigetti, Google, and IBM are all programmable with some manner of programming language, and not coincidentally, the number of qubits is two orders of magnitude fewer.
[1] https://en.m.wikipedia.org/wiki/Quadratic_unconstrained_bina...
There is no general purpose quantum computer that has 5,000 qubits. The D-Wave machines use quantum annealing. My reference was to the probabalistic gpc algorithm for solving TSP using annealing.
Every single thread that discusses D-Wave ends up with this same talking point about "universal" quantum computing. Yes, it's not yet another vaporware gate-model QC toy like Rigetti or Google have; it's a very specific sort of accelerator, somewhat akin to a GPU or a vector processor - not in terms of what it does, but in terms of requiring specific programming to make it useful. It's simply a vastly different architecture than gate-model QC: in many ways, it's a descendant of the analogue computers of the 60s and 70s.
The key differentiator here is that they've been able to scale their model from a couple hundred qubits to >5000, in production for anyone to use online. If you're a mathematician and you can actually model your problems this way, they have a nice SDK and it's very usable. There's every reason to assume that they'll have 10k qubits with even more connectivity in a few years, and they have this hybrid solver thing which takes in 10k+ variables already, so it's clear they believe in the problem model itself.
I just wish I could make it do more - my layman's interest has only taken me far enough to get a basic idea of what's going on for curiosity's sake. I think you need to be a mathematician in order to be able to do anything serious with it, right now.
This is like complaining about GPUs not being general purpose. Sure, that's a criticism, but it's not actually that valid.
In general, these days, people, especially technical, usually equate “computer” to “programmable computer”. This is as evidenced by the continual confusion as to what a D-Wave machine does and how they’re inequivalent to universal gate-based architectures.
A lot of folks these days call the kind of ‘computer’ that D-Wave is an “accelerator”.
Yes, absolutely it is. Just like how Babbage's difference engine was a computer, just like how a calculator is a computer. It's not a stored-program Von-Neumann turing complete thing, no, but that's clearly not the point - if you want one of those, wouldn't you just go to Intel et al?
The point of the D-Wave machine is to make super specialized optimization functions fast. Most of us, myself included, barely understand what those are or why they're useful. People interested in ML and neural networks, on the other hand, may find a processor designed intrinsically to work on entire graphs at a time to be somewhat useful. Maybe it's not big enough to do that yet, but ENIAC wasn't big enough to run Firefox - was it useless?
More info here, and note there is an iOS app too (Concorde TSP on the App Store) that you can play with that solves TSP to optimality: http://www.math.uwaterloo.ca/tsp/concorde.html