BCS pairing in a trapped dipolar Fermi gase

Abstract

We present a detailed study of the BCS pairing transition in a trapped polarized dipolar Fermi gas. In the case of a shallow nearly spherical trap, we find the decrease of the transition temperature as a function of the trap aspect ratio and predict the existence of the optimal trap geometry. The latter corresponds to the highest critical temperature of the BCS transition for a given number of particles. We also derive the phase diagram for an ultracold trapped dipolar Fermi gases in the situation, where the trap frequencies can be of the order of the critical temperature of the BCS transition in the homogeneous case, and find the critical value of the dipole-dipole interaction energy, below which the BCS transition ceases to exist. The critical dipole strength is obtained as a function of the trap aspect ratio. Alternatively, for a given dipole strength there is a critical value of the trap anisotropy for the BCS state to appear. The order parameter calculated at criticality, exhibits nover non-monotonic behavior resulted from the combined effect of the confining potential and anisotropic character of the interparticle dipole-dipole interation.

14 pages, 3 figures

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Cited by in corpus (8)

• Cold and Ultracold Molecules: Science, Technology, and Applications
• Condensed Matter Theory of Dipolar Quantum Gases
• The Fulde-Ferrell-Larkin-Ovchinnikov state for ultracold fermions in lattice and harmonic potentials: a review
• Collective modes, stability and superfluid transition of a quasi-two-dimensional dipolar Fermi gas
• Vortices and vortex lattices in quantum ferrofluids
• The stability and free expansion of a dipolar Fermi gas
• Ground state of an ultracold Fermi gas of tilted dipoles in elongated traps
• Stability of quantum degenerate Fermi gases of tilted polar molecules