Dynamical Creation of Fractionalized Vortices and Vortex Lattices
  We investigate dynamic creation of fractionalized half-quantum vortices in Bose-Einstein condensates of sodium atoms. Our simulations show that both individual half-quantum vortices and vortex lattices can be created in rotating optical traps when additional pulsed magnetic trapping potentials are applied. We also find that a distinct periodically modulated spin-density-wave spatial structure is always embedded in square half-quantum vortex lattices; this structure can be conveniently probed by taking absorption images of ballistically expanding cold atoms in a Stern-Gerlach field. 
An-Chun Ji, W. M. Liu (CAS), Jun Liang Song and Fei Zhou (UBC)