Trapping and Cooling of Atoms

In this chapter, we introduce the basics for confining and cooling samples of atoms at the gaseous state. First, we discuss the need of very low temperatures for achieving quantum degeneracy in the presence of concomitant effects due to several sources of atomic interactions. The latter are more prominent at high density, therefore setting an upper bound on both density and temperature of the atomic gas. Then, we remind some notions of atomic physics necessary to understand the mechanical action of light on atoms, the radiation pressure resulting in their slowing and cooling. We then describe two classes of purely conservative traps based on the presence of magnetic and electric dipole moments in the atoms and the related cooling mechanism based on forced evaporation. Particular care is taken to discuss the limits of each trapping and cooling technique, as this has played and still plays a major role in determining optimal experimental configurations for achieving quantum degeneracy.