Adiabatic loading of bosons into optical lattices

The entropy-temperature curves are calculated for noninteracting bosons in a three-dimensional (3D) optical lattice and a 2D lattice with transverse harmonic confinement for ranges of depths and filling factors relevant to current experiments. We demonstrate regimes where the atomic sample can be significantly heated or cooled by adiabatically changing the lattice depth. We indicate the critical points for condensation in the presence of a lattice and show that the system can be reversibly condensed by changing the lattice depth. We discuss the effects of interactions on our results and consider nonadiabatic processes.