Abstract
The last lecture, devoted to sideband cooling, gave us the opportunity to review the phase-space density that can be expected to be achieved in a radiative cooling experiment. We examined the limits imposed by collective effects in light-illuminated gases, in particular due to multiple scattering of spontaneously emitted photons. We outlined some remedies, such as confinement in a trap with a high oscillation frequency. This led us to a final cooling mechanism, sideband cooling, well suited to an assembly of atoms confined to the sites of an optical lattice. Finally, since the major obstacle to obtaining degenerate gases is the multiple scattering of photons emitted spontaneously during cooling, we ended this lecture by tackling a recurring question in the field: is spontaneous emission, which is at the root of the multiple scattering problem, indispensable to laser cooling of atoms?
