Coupling artificial atoms to light and sound

Artificial atoms made from superconducting circuits can be coupled both to light and to sound. Of special interest is when this is done in the quantum regime such that the modes that the atom couples to are free from excitations, i.e. the atom couples to the quantum vacuum of the modes. Both the electromagnetic quantum vacuum and the phononic quantum vacuum can be studied. Here we will describe two different experiments carried out at mK-temperatures and at microwave frequencies