Quantum Computing Stack Exchange is a question and answer site for engineers, scientists, programmers, and computing professionals interested in quantum computing. It only takes a minute to sign up.
Sign up to join this community
We have been reading about quantum computers being developed and tested in labs.
And also, we have quantum simulator programs that use limited virtual qubits (up to 30-40 qubits if cloud-based). And we have also started learning new quantum computing languages like Q#.
But do we really have actual commercial quantum computers ready with physical qubits?
That depends on your definitions of "commercial" and of "quantum computer".
The company D-Wave Systems has been offering what they call quantum computers commercially since 2011. Many things seem to point towards those being adiabatic quantum computers (though people disagree on this). That doesn't quite fit the kind of quantum computers that are becoming popular right now though. You can check this question and its answers for more information on that discussion.
Companies such as IBM in the other hand are offering access to circuit model quantum computers (with physical qubits). IBM specifically does this in the IBM Q project via their website and a programming interface. They cooperate with commercial companies to explore possibilities in the quantum computing field. (A similar offer is available from Rigetti Computing via their Rigetti Forrest project.) That's not what most people would call "commercial quantum computers" though.
So the answer truly is: It depends.
Ready for useful large scale applications? No.
However there do exist machines such as IBM's Quantum Experience with real physical qubits on a chip as well as Google announcing this month a new machine with 72 qubits.
D-Wave likes to tag itself as the first commercially available quantum computer however determining if it is indeed quantum seems to have been left as an exercise to the user. The D-Wave is available for commercial applications for a hefty price if you'd like to purchase a machine.
From an article I read a while ago, it seems like IBM has a 20-qbit quantum computing as a service (QCAAS as I'd like to call it).
They officially call it IBM Q: https://www.research.ibm.com/ibm-q/
Here's an excerpt from the linked article (Nov 10, 2017):
IBM makes 20 qubit quantum computing machine available as a cloud service
IBM has been offering quantum computing as a cloud service since last year when it came out with a 5 qubit version of the advanced computers.
Today, the company announced that it’s releasing 20-qubit quantum computers, quite a leap in just 18 months.
Commercially, no. But it is something that companies such as Intel have been working on. In-fact, Intel recently announced its new 49-qubit quantum chip & neuromorphic chip.
