Observation of a two-dimensional Fermi gas of atoms

We have prepared a degenerate gas of fermionic atoms which move in two dimensions while the motion in the third dimension is "frozen" by tight confinement and low temperature. {\it In situ} imaging provides direct measurement of the density profile and temperature. The gas is confined in a defect-free optical potential, and the interactions are widely tunable by means of a Fano--Feshbach resonance. This system can be a starting point for exploration of 2D Fermi physics and critical phenomena in a pure, controllable environment.