Phase-space deformation of a trapped dipolar Fermi gas

We consider a system of quantum degenerate spin-polarized fermions in a harmonic trap at zero temperature, interacting via dipole-dipole forces. We introduce a variational Wigner function to describe the deformation and compression of the Fermi gas in phase space and use it to examine the stability of the system. We emphasize the important roles played by the Fock exchange term of the dipolar interaction, which results in a nonspherical Fermi surface.