[0] - https://www.nature.com/articles/nature23879
[1] - https://ai.google/research/teams/applied-science/quantum/ - see 'Near-Term Applications'
I don't really know much about the topic but my understanding is that it could potentially be more dense then the theoretic limit of current transistor sizes.
Science fiction has hypothesized about quantum computing that involves macroscopically-sized bits of carefully constructed matter running a number of qubits best described with scientific notation, but it's not clear how one would set up problems or read anything out of such a thing.
Current sizes of quantum bits: cavities are cm to mm scale; transmons and photonics can be much smaller, but nowhere near the size of modern transistors; ions need to be trapped in something and usually the scale is not better than the other options.
There is the hope that qubits can be made in silicon and use lithographic technologies, but then at best we will reach the density of current CPUs (but such a thing is science fiction at the moment).
Wait.. patent pending. There's probably an unreasonably large some of money to be made being able to sell that label to unwitting trend-hoppers.