Laser cooling and trapping techniques have recently been extended to species with large magnetic moments. This spectacular breakthrough has led to the observation of new macroscopic quantum phenomena, which we will address in this lecture. In particular, we will study the transition of these assemblies of atoms from their usual gaseous state to a liquid state stabilized by a purely quantum effect. We will also describe the emergence of a supersolid state, which possesses both superfluid properties, such as viscosity-free flow, and the characteristics of a solid, with a well-established spatial order.