Stable 2D skyrmion and half-skyrmion in three-component Bose-Einstein condensates

Skyrmion spin textures were experimentally created in an antiferromagnetic spin-1 Bose-Einstein condensate by Choi et al. However, the stability of 2D skyrmion excitations is still controversial. Theoretical calculations show that 2D skyrmion excitations are energetically unstable. However, we find that the 2D skyrmion as well as the half-skyrmion can be naturally generated from a vortex-free Gaussian wave packet by incorporating spin-orbit coupling into three-component Bose-Einstein condensates.