强相互作用费米气体在谐振子势中的干涉演化  

Evolution of interference patterns of strongly interacting Fermi gases in a harmonic trap

作　　者：文文 李慧军[2] 陈秉岩[1] 

机构地区：[1]河海大学常州校区数理部,常州213022 [2]浙江师范大学非线性研究所,金华321004

出　　处：《物理学报》2012年第22期72-79,共8页Acta Physica Sinica

基　　金：国家自然科学基金(批准号:11105039);中央高校基本科研业务费(批准号:2012B05714,2009B31614);河海大学博士科研启动费资助的课题~~

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.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.

关 键 词：超流费米原子气体 快速磁场扫描 光晶格 干涉条纹 

分 类 号：O562[理学—原子与分子物理] O512[理学—物理]