Properties of the density-wave phase of a two-dimensional dipolar Fermi gas

Abstract

The rapid progress in the production and cooling of molecular gases indicates that experimental studies of quantum gases with a strong dipolar interaction is soon within reach. Dipolar gases are predicted to exhibit very rich physics including quantum liquid crystal phases such as density-waves as well as superfluid phases, both of which play an important role for our understanding of strongly correlated systems. Here, we investigate the zero temperature properties of the density-wave phase of a two-dimensional (2D) system of fermonic dipoles using a conserving Hartree-Fock theory. We calculate the amplitude of the density waves as a function of the dipole moment and orientation with respect to the 2D plane. The stripes give rise to a 1D Brillouin zone structure, and the corresponding quasiparticle spectrum is shown to have gapped as well as gapless regions around the Fermi surface. As a result, the system remains compressible in the density-wave phase, and it collapses for strong attraction. We show that the density-waves has clear signatures in the momentum distribution and in the momentum correlations. Both can be measured in time-of-flight experiments. Finally, we discuss how the striped phase can be realised with experimentally available systems.

9 pages, 7 figures. Due to copyright reasons this version is not identical to the published version

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Cited by in corpus (3)

• Coexistence of density wave and superfluid order in a dipolar Fermi gas
• Second-order interaction corrections to the Fermi surface and the quasiparticle properties of dipolar fermions in three dimensions
• Tilted dipolar bosons in the quasi-two-dimensional regime: From liquid stripes to droplets