INTERACTING FERMI GAS IN A HARMONIC TRAP

In view of ongoing experiments to trap ultracold spin-polarized Li-6, we study various properties of an interacting Fermi gas in a harmonic trap, taking the discrete nature of the unperturbed harmonic trap leve ls into account exactly, As Li-6 has a rather large and negative scatt ering length, we focus on the effects of the attractive atom-atom inte raction on several thermodynamic properties, and on the momentum and d ensity distributions. The dependence of the chemical potential, the sp ecific heat, and the density and momentum distributions on the number of particles in the trap is obtained. We also calculate the energy of the gas. Comparison is made with results of a semiclassical calculatio n and with the properties of a noninteracting gas. We find that the ef fect of the interactions is rather large for realistic trap frequencie s. Hence it is important to include these interactions in any quantita tive predictions relevant for experiments.