Exotic roton excitations in quadrupolar Bose–Einstein condensates Journal Article

Author(s): Lahrz, Martin; Lemeshko, Mikhail P; Mathey, Ludwig
Article Title: Exotic roton excitations in quadrupolar Bose–Einstein condensates
Affiliation IST Austria
Abstract: We investigate the occurrence of rotons in a quadrupolar Bose–Einstein condensate confined to two dimensions. Depending on the particle density, the ratio of the contact and quadrupole–quadrupole interactions, and the alignment of the quadrupole moments with respect to the confinement plane, the dispersion relation features two or four point-like roton minima or one ring-shaped minimum. We map out the entire parameter space of the roton behavior and identify the instability regions. We propose to observe the exotic rotons by monitoring the characteristic density wave dynamics resulting from a short local perturbation, and discuss the possibilities to detect the predicted effects in state-of-the-art experiments with ultracold homonuclear molecules.
Keywords: quadrupolar quantumgas; quadrupole-quadrupole interaction; rotons; homonuclear molecules
Journal Title: New Journal of Physics
Volume: 17
ISSN: 1367-2630
Publisher: IOP Publishing Ltd.  
Date Published: 2015-04-01
Start Page: Article number: 045005
Copyright Statement: CC BY 3.0
Sponsor: We acknowledge support from the Deutsche Forschungsgemeinschaft through the SFB 925 and the Hamburg Centre for Ultrafast Imaging, and from the Landesexzellenzinitiative Hamburg, which is supported by the Joachim Herz Stiftung.
DOI: 10.1088/1367-2630/17/4/045005
Open access: yes (OA journal)
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