We theoretically investigate four types of dynamical instability, in particular the periodic and oscillatory type $I_O$, in an antiferromagnetic spin-1 Bose-Einstein condensate in a nonzero magnetic field, by employing the coupled-mode theory and numerical method. This is in sharp contrast to the dynamical stability of the same system in zero field. Remarkably, a pattern transition from a periodic dynamical instability $I_O$ to a uniform one ${\mathit{\text{III}}}_O$ occurs at a critical magnetic field. All four types of dynamical instability and the pattern transition are ready to be detected in ${}^{23}\mathrm{Na}$ condensates within the availability of the current experimental techniques.

• Received 4 March 2016

DOI:https://doi.org/10.1103/PhysRevA.93.053628