Exotic roton excitations in quadrupolar Bose-Einstein condensates

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.

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Cited by in corpus (9)

• Rotation of cold molecular ions inside a Bose-Einstein condensate
• Ultralong-range order in the Fermi-Hubbard model with long-range interactions
• Quantum phase transition of a two-dimensional quadrupolar system
• Density functional theory for strongly-correlated bosonic and fermionic ultracold dipolar and ionic gases
• Quadrupolar Excitons in MoSe${}_2$ Bilayers
• Quench dynamics of disordered quadrupolar Bose-Einstein condensates
• Beyond-mean-field phases of rotating dipolar condensates
• Quantum Gases of Dipoles, Quadrupoles and Octupoles in Gross-Pitaevskii Formalism with Form Factor
• Low-energy scatterings and pseudopotential of polarized quadrupoles