Would it be possible to make a quantum computer with fluidic logic (https://en.m.wikipedia.org/wiki/Fluidics), using a superfluid, like liquid Helium-4, as the the "current"?
I think the question I would ask is, what are you trying to gain from switching to this very awkward material? The only advantage I would see is reduction of friction losses, but I'm not sure that's even a major concern in fluidics. On the downside, now you have a device that needs to stay below 2K, and you get hard-to-deal-with side effects.