| Results from the production and study of the first degenerate Fermi gas of atoms are presented. By adapting the magnetic trapping and evaporative cooling techniques that were used to produce atomic Bose-Einstein condensation, a gas of fermionic 40K atoms is cooled into the quantum regime. The fundamental difficulty in cooling a gas of fermionic, compared to bosonic, atoms is the lack of rethermalizing collisions in a spin polarized sample. This obstacle is explored in cold collision studies and then overcome by magnetically trapping two spinstates of 40K and developing a technique for simultaneous evaporative cooling.; The ability to cool an interacting, two-component gas to one-quarter of the Fermi temperature is demonstrated. A spin-polarized, ideal gas can be cooled to as low as ∼0.17 times the Fermi temperature. The emergence of quantum behavior at low temperature is observed both as "excess" energy in the gas and a distortion of the momentum distribution compared to the classical expectation. Furthermore, the effect of the Fermi-Dirac statistics of the gas on individual collisions via Pauli blocking is observed through measurements of the thermal relaxation time. |
