IBM Will Sell 50-Qubit Universal Quantum Computer In the Next Few Years (arstechnica.co.uk)

Months after laying the groundwork for offerings in emerging tech categories such as artificial intelligence and blockchain, IBM sees quantum computers as a big, if nascent, business opportunity. From a report on ArsTechnica: IBM will build and sell commercial 50-qubit universal quantum computers, dubbed IBM Q, "in the next few years." No word on pricing just yet, but I wouldn't expect much change from $15 million -- the cost of a non-universal D-Wave quantum computer. In other news, IBM has also opened up an API (sample code available on Github) that gives developers easier access to the five-qubit quantum computer currently connected to the IBM cloud. Later in the year, IBM will release a full SDK, further simplifying the process of building quantum software. You can't actually do much useful computation with five qubits, mind you, but fortunately IBM also has news there: the company's quantum simulator can now simulate up to 20 qubits. The idea is that developers should start thinking about potential 20-qubit quantum scenarios now, so they're ready to be deployed when IBM builds the actual hardware.

Comments

Quantum supremacy tests will come first

[JoshuaZ]

One of the major issues is the need for actual empirical evidence that quantum computers can do things that classical computers cannot with reasonable time constraints. Right now, the general consensus is that if we understand correctly the laws of physics this should be the case, but there are some people who are very prominent holdouts who are convinced that quantum computing will not scale. Gil Kalai is the most prominent https://gilkalai.wordpress.com/2014/03/18/why-quantum-computers-cannot-work-the-movie/. It is likely that before any 50 bit quantum computer we'll have already answered this question. The most likely answer will be using boson sampling systems https://en.wikipedia.org/wiki/Boson_sampling which in their simplest form give information about the behavior of photons when scattered in a simple way. Scott Aaronson and Alex Arkhipov showed that if a classical computer could efficiently duplicate boson sampling with only a small increase in time then some already existing conjectures in classical computational complexity had to be false. (In particular, the polynomial hierarchy would have to collapse and we're generally confident that isn't the case.) Boson sampling is much easier to implement than a universal quantum computer, although no one has any practical use of boson sampling at present.

All of that said, the "a few years" in the article is critical- it isn't plausible that a 50 qubit universal system will be sold in 5 years. But 10 or 20 years are plausible. It also isn't completely clear how practically useful a 50 qubit system would be. At a few hundred qubits one is clearly in the realm of having direct practical applications, but 50 is sort of in a fuzzy range.

What are its capabilities?

[OneHundredAndTen]

What kind of problems can this particular computer solve, within a reasonable time (hours? minutes!) that would take an ordinary PC - or even a massive classic supercomputer - decades, or even millennia, to solve?

Re:"Will"

[TechyImmigrant]

>The article doesn't say who they'll deliver it to.
>What exactly will it be useful for? Factoring 50-bit numbers? Any ideas?
>$15 million seems an awful lot of money just for bragging rights. It'd better come in a really pretty box so people can put it in the lobby when they get bored with it.

If it's a general computer then yes. You could implement Shor's algorithm for factoring, Grover's algorithm for inverting mappings (to find keys). There are a handful of non crypto related algorithms for things like simulated annealing.

What no quantum computer to date has done and what a 50 bit quantum computer for $15,000,000 will not do is compute anything that can't be computed more cheaply or efficiently on a traditional computer.

I remain a skeptic that quantum computers can scale up to useful sizes. The rest of the universe wants to bring that low entropy state back into line with the rest of reality and it has succeeded every time so far.