arXiv:1702.03663 · Physical Review A
Single and multiple vortex rings in three-dimensional Bose-Einstein condensates: Existence, stability, and dynamics
Wenlong Wang, R. N. Bisset, Christopher Ticknor, R. Carretero-González, D. J. Frantzeskakis, Lee A. Collins, P. G. Kevrekidis
Abstract
In the present work, we explore the existence, stability, and dynamics of single- and multiple-vortex-ring states that can arise in Bose-Einstein condensates. Earlier works have illustrated the bifurcation of such states in the vicinity of the linear limit for isotropic or anisotropic three-dimensional harmonic traps. Here, we extend these states to the regime of large chemical potentials, the so-called Thomas-Fermi limit, and explore their properties such as equilibrium radii and inter-ring distance for multi-ring states, as well as their vibrational spectra and possible instabilities. In this limit, both the existence and stability characteristics can be partially traced to a particle picture that considers the rings as individual particles oscillating within the trap and interacting pairwise with one another. Finally, we examine some representative instability scenarios of the multi-ring dynamics, including breakup and reconnections, as well as the transient formation of vortex lines.