Nonadiabatic production of spinor condensates with a QUIC trap

A recent experiment [Xiu-Quan Ma {\it et al.}, Chin. Phys. Lett. {\bf 22}, 1106 (2005)] reported the observation of a multi-component spinor condensate when the magnetic field of a QUIC trap containing a spin polarized condensate was switched off. Our theoretical study show that this phenomena can be described within a general framework of the nonadiabatic Landau-Zener transition theory. We will discuss the population transfers at the zero field level crossing for this interesting case involving more than two levels, and provide a detailed understanding of the relevant nonadiabatic behavior.