Spectral and dynamical analysis of a single vortex ring in anisotropic harmonically trapped three-dimensional Bose-Einstein condensates

Journal Article · Wed Sep 26 00:00:00 EDT 2018 · Physical Review A

DOI:https://doi.org/10.1103/PhysRevA.98.033609· OSTI ID:1492669

Ticknor, Christopher ^[1]; Wang, Wenlong ^[2]; Kevrekidis, P. G. ^[3]

---

1. Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
2. Royal Inst. of Technology, Stockholm (Sweden). Dept. of Theoretical Physics
3. Univ. of Massachusetts, Amherst, MA (United States). of Dept. of Mathematics and Statistics

Here in the present work, motivated by numerous recent experimental developments we revisit the dynamics of a single vortex ring in anisotropic harmonic traps. At the theoretical level, we start from a general Lagrangian dynamically capturing the evolution of a vortex ring and not only consider its spectrum of linearized excitations, but also explore the full nonlinear dynamical evolution of the ring as a vortical filament. The theory predicts that the ring is stable for 1 ≤ λ ≤ 2, where λ = ω_z /ω_r is the ratio of the trapping frequencies along the z and r axes, i.e., for spherical to slightly oblate condensates. We compare this prediction with direct numerical simulations of the full three-dimensional Gross-Pitaevskii equation (GPE) capturing the linearization spectrum of the ring for different values of the chemical potential and as a function of the anisotropy parameter λ . We identify this result as being only asymptotically valid as the chemical potential μ → ∞, revealing how the stability interval narrows and, in particular, its upper bound decreases for finite μ. Finally, we compare at the dynamical level the results of the GPE with the ones effectively capturing the ring dynamics, revealing the unstable evolution for different values of λ, as well as the good agreement between the two.

• Research Organization: Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
• Sponsoring Organization: USDOE National Nuclear Security Administration (NNSA)
• Grant/Contract Number: 89233218CNA000001; AC52-06NA25396
• OSTI ID: 1492669
• Alternate ID(s): OSTI ID: 1473996
• Report Number(s): LA-UR-18-26982; PLRAAN
• Journal Information: Physical Review A, Vol. 98, Issue 3; ISSN 2469-9926
• Publisher: American Physical Society (APS)
• Country of Publication: United States
• Language: English

Related Subjects

74 ATOMIC AND MOLECULAR PHYSICS
Atomic
Nuclear and Particle Physics