Yes, they are up to about four bits, I follow some of the papers. I think we have a decade or two before we need to worry. Then I’ll switch to random detanglement encryption with noncoherent spin state, because by then our computers will also use QC at the core.
They need some pretty stiff cryogenics to operate now. If that can be brought up to, say, the temperature of liquid nitrogen, then it will be easier to get one in every office, if not in every laptop. STILL, Uncle Sam’s machines will be on the cutting edge. The impractical does not stop them.