[eigenket]

Speaking as a researcher in quantum computing (albiet completely on the theory side, with no practical knowledge of experiments). It seems that actually making a quantum computer which is useful (i.e. has error rate below the threshold you need for error correction to work) is incredibly difficult. I wouldn't be surprised if various secret agencies (specifically in the USA and China) have tried, but I would be quite surprised if they had succeded.

(I deleted my previous edit because I had misread part of what you wrote.)