Ferromagnetic spin-1 Bose-Einstein condensates in the broken-axisymmetric phase support polar-core spin vortices (PCVs), which are intimately linked to the nonequilibrium dynamics of the system. For a purely transversely magnetized system, the Turner point-vortex model predicts that PCVs behave like massive charged particles interacting via a two-dimensional Coulomb potential. We test the accuracy of the Turner model for two oppositely charged PCVs, via comparisons with numerical simulations. While the bare Turner model shows discrepancies with our numerical results, we find that a simple rescaling of the PCV mass gives much better agreement. This can be explained via a phenomenological damping arising from coupling to modes extrinsic to the point-vortex phase space. We also identify the excitations produced following PCV annihilation, which help elucidate recent phase ordering results. We extend the Turner model to cases where the system is magnetized both transversally and axially, identifying a crossover to scalar vortex dynamics for increasing external Zeeman field.

• Received 22 October 2020
• Revised 14 December 2020
• Accepted 27 January 2021

DOI:https://doi.org/10.1103/PhysRevResearch.3.013154

Published by the American Physical Society under the terms of the Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article's title, journal citation, and DOI.

Published by the American Physical Society