Collective excitations of a dipolar Bose-Einstein condensate

• Published in: Physical review letters Vol. 105; no. 4; p. 040404
• Main Authors: Bismut, G, Pasquiou, B, Maréchal, E, Pedri, P, Vernac, L, Gorceix, O, Laburthe-Tolra, B
• Format: Journal Article
• Language: English
• Published: United States American Physical Society 23-07-2010
• Subjects: ASPECT RATIO; ATOMIC MODELS; ATOMS; BOSE-EINSTEIN CONDENSATION; CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; COLLECTIVE EXCITATIONS; Condensed Matter; DIMENSIONLESS NUMBERS; DIPOLES; ENERGY-LEVEL TRANSITIONS; EXCITATION; GEOMETRY; INTERACTIONS; MATHEMATICAL MODELS; MATHEMATICS; MODIFICATIONS; MULTIPOLES; Physics; Quantum Gases; Quantum Physics; SIMULATION; THOMAS-FERMI MODEL; TRAPPING; collective excitations; Bose Einstein condensate; dipole-dipole interaction; collective modes; dipolar quantum gas
• ISSN: 0031-9007; 1079-7114
• DOI: 10.1103/physrevlett.105.040404

We have measured the effect of dipole-dipole interactions on the frequency of a collective mode of a Bose-Einstein condensate. At relatively large numbers of atoms, the experimental measurements are in good agreement with zero temperature theoretical predictions based on the Thomas-Fermi approach. Experimental results obtained for the dipolar shift of a collective mode show a larger dependency to both the trap geometry and the atom number than the ones obtained when measuring the modification of the condensate aspect ratio due to dipolar forces. These findings are in good agreement with simulations based on a Gaussian ansatz.