Multiresonant Spinor Dynamics in a Bose-Einstein Condensate

We analyze the spinor dynamics of a Rb-87 F=2 condensate initially prepared in the m(F)=0 Zeeman sublevel. We show that this dynamics, characterized by the creation of correlated atomic pairs in m(F)=+/- 1, presents an intriguing multiresonant magnetic-field dependence induced by the trap inhomogeneity. This dependence is directly linked to the most unstable Bogoliubov spin excitations of the initial m(F)=0 condensate, showing that, in general, even a qualitative understanding of the pair-creation efficiency in a spinor condensate requires a careful consideration of the confinement.