Internal structure and stability of vortices in a dipolar spinor Bose-Einstein condensate

Borgh, Magnus O. and Lovegrove, Justin and Ruostekoski, Janne (2017) Internal structure and stability of vortices in a dipolar spinor Bose-Einstein condensate. Physical review a, 95 (5). ISSN 1050-2947

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Abstract

We demonstrate how dipolar interactions can have pronounced effects on the structure of vortices in atomic spinor Bose-Einstein condensates and illustrate generic physical principles that apply across dipolar spinor systems. We then find and analyze the cores of singular vortices with non-Abelian charges in the point-group symmetry of a spin-3 $^52$Cr condensate. Using a simpler model system, we analyze the underlying dipolar physics and show how a characteristic length scale arising from the magnetic dipolar coupling interacts with the hierarchy of healing lengths of the s-wave scattering, and leads to simple criteria for the core structure: When the interactions both energetically favor the ground-state spin condition, such as in the spin-1 ferromagnetic phase, the size of singular vortices is restricted to the shorter spin-dependent healing length. Conversely, when the interactions compete (e.g., in the spin-1 polar phase), we find that the core of a singular vortex is enlarged by increasing dipolar coupling. We further demonstrate how the spin-alignment arising from the interaction anisotropy is manifest in the appearance of a ground-state spin-vortex line that is oriented perpendicularly to the condensate axis of rotation, as well as in potentially observable internal core spin textures. We also explain how it leads to interaction-dependent angular momentum in nonsingular vortices as a result of competition with rotation-induced spin ordering. When the anisotropy is modified by a strong magnetic field, we show how it gives rise to a symmetry-breaking deformation of a vortex core into a spin-domain wall.

Item Type:
Journal Article
Journal or Publication Title:
Physical review a
Additional Information:
© 2017 American Physical Society
Uncontrolled Keywords:
/dk/atira/pure/subjectarea/asjc/3100/3107
Subjects:
ID Code:
123639
Deposited By:
Deposited On:
26 Feb 2018 15:30
Refereed?:
Yes
Published?:
Published
Last Modified:
30 Sep 2020 07:31