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Q: Fachverband Quantenoptik und Photonik
Q 26: Quantengase: Fermionen
Q 26.3: Vortrag
Dienstag, 3. März 2009, 17:00–17:15, VMP 6 HS-A
Thermodynamic and Dynamic Properties of a Dipolar Fermi Gas — •Aristeu Rosendo Pontes Lima1 and Axel Pelster1,2 — 1Institut für Theoretische Physik, Freie Universität Berlin, Arnimallee 14, 14195 Berlin, Germany — 2Fachbereich Physik, Universität Duisburg-Essen, Lotharstrasse 1, 47048 Duisburg, Germany
We present a variational Hartree-Fock approach to treat a Fermi gas of fully polarized particles interacting through a dipole-dipole potential. Starting from a Thomas-Fermi approximation for the Wigner function, we obtain analytical information on this system from a parabolic ansatz, which is exact in the non-interacting limit and discuss the resulting equilibrium properties of the cloud. For example, we analyze the how the Thomas-Fermi radii, the aspect ratio and the release energy depend on the dipolar interaction strength. We confirm the numerically indicated nonexistence of absolute stability [1] and attribute it to the incapability of the Fermi pressure to suppress the attractive part of the dipole-dipole interaction. This is in contradiction to the dipolar Bose gas [2], which is stabilized by the contact interaction. Furthermore, we analyze the frequencies of the collective oscillations of a dipolar Fermi gas within a variational sum-rule approach.
[1] L. He, J.-N. Zhang, Y. Zhang, and S. Yi, Phys. Rev. A 77, 031605(R) (2007)
[2] C. Eberlein, S. Giovanazzi, and D.H.J. O’Dell, Phys. Rev. A 71, 033618 (2005)