At ETHZ there are different labs that combine both theory and experiment. In fact, the one that I am mostly interested about is quantum magnetism, with regard to theory. My current project as a 3rd year student is based on a new model that would describe the magnetic properties of materials at different temperatures. Now I mentioned those 3 unis in the US but the one I am really interested is Princeton and their quantum technologies’ department (Not quantum technologies with the essence of quantum computing though).