Long term dynamics of the splitting of a doubly quantized vortex in a two-dimensional condensate

We study the nonlinear dynamics of the splitting of a doubly quantized vortex in a trapped condensate. The dynamics is studied in detail by solving the Gross-Pitaevskii equation. The main dynamical features are explained in terms of a nonlinear three-level system. We find an analytical solution for the characteristics of the dynamics. It is concluded that the time scale for the splitting is mainly determined by the instability of the linearized system, and nonlinear effects contribute logarithmically.