So a supercomputer is a physics experiment? A lithography machine for producing microchips is a physics experiment?

I guess a fair threshold would be “when it can be run and maintained by engineers rather than scientists”. In which case, many quantum computers are indeed physics experiments.

Fair enough - sounds more like a problem with the specific study than with the quantum computer

In a way, regular computers are also physics experiments. As are fridges and cars. When does an experiment graduate to being a technology?