中文摘要：

通过数值求解超流序参量方程，研究了强相互作用费米气体从光晶格中释放后的干涉条纹在谐振子势中的演化．发现对于强相互作用的费米气体，膨胀时弹性碰撞使得干涉条纹模糊．为了消除原子间的弹性碰撞而获得近弹道膨胀，实验上采用了快速磁场扫描技术．数值模拟了强相互作用费米气体在膨胀前的快速磁场扫描过程，得到了清晰的干涉条纹，且发现干涉条纹在谐振子势中做长时间周期振荡．计算了在不同超流区域所形成的干涉条纹，与实验观测到的一致．

英文摘要：

We study the evolution of the interference patterns of strongly interacting Fermi gases in a harmonic trap after removal of the optical lattice, by numerically solving the superfluid order-parameter equation. We find that for the strongly interacting Fermi gas elastic collisions during the expansion blur the interference peaks. In order to obtain a nearly ballistic expansion, the fast magnetic field ramp technique is applied in experiment. We simulate the fast magnetic field ramp process before expansions of strongly interacting Fermi gases. We find that clear interference patterns are formed, and oscillate for a long time in the harmonic trap. We also calculate the interference patterns in different superfluid regimes, which accord with the experimental observations.