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

Borgh, Magnus O., Lovegrove, Justin and Ruostekoski, Janne (2017) Internal structure and stability of vortices in a dipolar spinor Bose-Einstein condensate. Physical Review A, 95, [053601].

Record type: Article

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.

Text
dipolar-structure-pra-final - Accepted Manuscript

Submitted date: 31 January 2017
Accepted/In Press date: 6 April 2017
e-pub ahead of print date: 1 May 2017
Keywords: cond-mat.quant-gas
Organisations: Mathematical Sciences, Applied Mathematics

Identifiers

Local EPrints ID: 407674
URI: http://eprints.soton.ac.uk/id/eprint/407674
ISSN: 1050-2947
PURE UUID: cee15917-91dc-4227-b0d4-d76b1e619305

Catalogue record

Date deposited: 22 Apr 2017 01:03

Contributors

Author: Magnus O. Borgh
Author: Justin Lovegrove