双势阱中玻色-爱因斯坦凝聚的绝热隧穿

研究了玻色-爱因斯坦凝聚体在双势阱中随着能级差绝热循环变化而发生的绝热隧穿.发现当相互作用较强且初态选择为凝聚体全部置于较浅势阱时,演化过程破坏绝热定理,而演化结果有可能回到初态,也有可能不回到初态,取决于演化周期的选择;另外还发现演化过程表现出对初态选择的依赖,具有不对称的特征.利用能级图和相图,对上述现象给出了解释. 关键词： 玻色-爱因斯坦凝聚 Landau-Zener模型 绝热隧穿

Adiabatic tunneling of Bose-Einstein condensate in double-well potential

We studied the adiabatic tunneling of Bose-Einstein condensates (BEC) in double-well potential with circle adiabatic variation of energy level spacing. We found that the adiabatic theorem is violated during the evolution of BEC, when the initial state is chosen such that all condensate atoms are in the shallow well and the interaction between atoms is strong enough. Furthermore, we found that the condensates can return to the initial state or not, depending on the evolution periods. In addition, we also found the evolution is dependent on the choice of initial state, which indicates an asymmetric character. With the help of the graph of energy levels and the phase diagram, we explained the results obtained.