Collision dynamics between stretched states of spin-2 87Rb Bose–Einstein condensates
We experimentally observed the time dependence of the spin populations of spin-2 87Rb Bose–Einstein condensates confined in an optical trap. The condensed atoms were initially populated in the stretched states |F=2,m F =+2〉 and |F=2,m F =−2〉 with several varieties of population imbalances. No spin-exchange collisions were observed in a weak magnetic field of 45 mG. The atom loss rate depended on the observed relative population of spin-states. We calculated the loss rate due to two-body inelastic collisions with the population imbalance using an experimentally estimated rate of 17.0(±1.9)×10−14 cm3 s−1 under the population balance. The calculations were in good agreement with the measurements. Our results show that the dependence of inelastic collisions on spin channels plays an important role in the time-evolution of spin populations.
PACS03.75.Mn 34.50.Pi 05.30.Jp
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