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Stability of a purely dipolar gas in a power-law potential

ORAL

Abstract

We solve the time-independent Gross–Pitaevskii equation numerically to explore the stability of a purely dipolar Bose–Einstein condensate (BEC) in a cylindrically-symmetric trap. The atoms are polarised and confined to a harmonic potential along the cylinder’s axis, and they are trapped in a general power-law potential (rn) in the perpendicular direction. We explore the effect of both the power law and the trap aspect ratio.

For small aspect ratios, we confirm the instability is seeded by high density at the centre of the trap. However, for larger aspect ratios this transforms into a roton-like instability, which is seeded by finite-k roton-like density oscillations. For high-n (box-like) potentials, we find that however large the aspect ratio is, a confined gas is always less stable than a completely uniform one as instability is seeded by the hard wall. Interestingly, we observe that a softer potential (n~7) actually produces a more homogeneous 2D-density than a simple box-potential.

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Presenters

  • Péter Juhász

    University of Oxford, Clarendon Laboratory, University of Oxford, Clarendon Laboratory, University of Oxford, Parks Road, Oxford OX1 3PU, United Kingdom

Authors

  • Péter Juhász

    University of Oxford, Clarendon Laboratory, University of Oxford, Clarendon Laboratory, University of Oxford, Parks Road, Oxford OX1 3PU, United Kingdom

  • Milan Krstajic

    University of Cambridge, Cavendish Laboratory, University of Cambridge; Clarendon Laboratory, University of Oxford, Clarendon Laboratory, University of Oxford, Parks Road, Oxford OX1 3PU, United Kingdom ; Cavendish Laboratory, University of Cambridge, J. J. Thomson Avenue, Cambridge CB3 0HE

  • David Strachan

    Clarendon Laboratory, University of Oxford, Parks Road, Oxford OX1 3PU, United Kingdom

  • Edward Gandar

    Clarendon Laboratory, University of Oxford, Parks Road, Oxford OX1 3PU, United Kingdom

  • Robert Smith

    University of Oxford, Clarendon Laboratory, University of Oxford, Parks Road, Oxford OX1 3PU, United Kingdom