[drdeca]

I thought a qubit could also be implemented with current going around a superconductor loop. Is that incorrect?

[ben_w]

You can implement them like that. Anything that has a quantum state that doesn’t decohere too fast will work. The hard part thus far has been that almost everything does decohere too fast.

[Denvercoder9]

No, that's indeed a quite popular approach.