Collective motion of polarized dipolar Fermi gases in the hydrodynamic regime

Recently, a seminal stimulated Raman adiabatic passage (STIRAP) experiment allowed the creation of (KRb)-K-40-Rb-87 molecules in the rovibrational ground state [K.-K. Ni et al., Science 322, 231 (2008)]. To describe such a polarized dipolar Fermi gas in the hydrodynamic regime, we work out a variational time-dependent Hartree-Fock approach. With this we calculate dynamical properties of such a system, for instance, the frequencies of the low-lying excitations and the time-of-flight expansion. We find that the dipole-dipole interaction induces anisotropic breathing oscillations in momentum space. In addition, after release from the trap, the momentum distribution becomes asymptotically isotropic, while the particle density becomes anisotropic.