Spin excitations in a Fermi gas of atoms.

We have experimentally investigated a spin excitation in a quantum degenerate Fermi gas of atoms. In the hydrodynamic regime the damping time of the collective excitation is used to probe the quantum behavior of the gas. At temperatures below the Fermi temperature we measure up to a factor of 2 reduction in the excitation damping time compared to the classical expectation. In addition, we observe a strong excitation energy dependence for this quantum statistical effect.