Vortex Ring Dynamics in Trapped Bose-Einstein Condensates

Abstract

We use the time-dependent Gross-Pitaevskii equation to study the motion of a vortex ring produced by phase imprinting on an elongated cloud of cold atoms. Our approach models the experiments of Yefsah et. al. [Nature \textbf{499}, 426] on ${}^6$Li in the BEC regime where the fermions are tightly bound into bosonic dimers. We find ring oscillation periods which are much larger than the period of the axial harmonic trap. Our results lend further strength to Bulgac et. al.'s arguments [arXiv: 1306.4266] that the "heavy solitons" seen in those experiments are actually vortex rings. We numerically calculate the periods of oscillation for the vortex rings as a function of interaction strength, trap aspect ratio, and minimum vortex ring radius. In the presence of axial anisotropies the rings undergo complicated internal dynamics where they break into sets of vortex lines, then later combine into rings. These structures oscillate with a similar frequency to simple axially symmetric rings.

6 pages, 6 figures, revtex4; new subsection and figure addressing axial asymmetry, added references to sections 2 and 3, minor changes to section 5, main conclusions unchanged

References in corpus (5)

• Weakly bound dimers of fermionic atoms
• Oscillations and interactions of dark and dark-bright solitons in Bose-Einstein condensates
• Traveling Dark Solitons in Superfluid Fermi Gases
• Snake instability of dark solitons in fermionic superfluids
• Bending-wave Instability of a Vortex Ring in a Trapped Bose-Einstein Condensate

Cited by in corpus (18)

• Observation of Solitonic Vortices in Bose-Einstein Condensates
• Motion of a Solitonic Vortex in the BEC-BCS Crossover
• From Planar Solitons to Vortex Rings and Lines: Cascade of Solitonic Excitations in a Superfluid Fermi Gas
• Critical transport and vortex dynamics in a thin atomic Josephson junction
• Many-Body Quantum Dynamics in the Decay of Bent Dark Solitons of Bose-Einstein Condensates
• Life Cycle of Superfluid Vortices and Quantum Turbulence in the Unitary Fermi Gas
• Phase Imprinting in Equilibrating Fermi Gases: The Transience of Vortex Rings and Other Defects
• Stability and dispersion relations of three-dimensional solitary waves in trapped Bose-Einstein condensates
• Solitonic Vortices in Bose-Einstein Condensates
• Collective modes of a soliton train in a Fermi superfluid
• Symmetry-breaking instability of leapfrogging vortex rings in a Bose-Einstein condensate
• Collective oscillations of a Bose-Einstein condensate induced by a vortex ring
• Core filling and snaking instability of dark solitons in spin-imbalanced superfluid Fermi gases
• Shock Waves in a Superfluid with Higher-Order Dispersion
• Vortex rings and vortex ring solitons in shaken Bose-Einstein condensate
• Perturbation-induced defects in trapped superfluids exhibit generic behavior
• Controlled generation of 3D vortices in driven atomic Josephson junctions
• Dynamics of a solitonic vortex in an anisotropically trapped superfluid