The Interference Effect of a Bose–Einstein Condensate in a Ring-Shaped Trap

We have studied the interference effect of a Bose–Einstein condensate expanding in a ring-shaped trap. The dynamic process of the condensate is analyzed based on the Gross–Pitaevskii equation. Our numerical results show that a petal-like interference pattern is formed during expansion within the ring-shaped trap. The petal number depends on the evolution time, which can be well explained by the interference of two flows of the condensate.