偶极玻色-爱因斯坦凝聚体中孤子碰撞的理论研究

Theoretical investigation on collisions between two solitons in dipolar Bose-Einstein condensate

对准一维情形下具有偶极相互作用的玻色-爱因斯坦凝聚体(Bose-Einsteincondensate,BEC)中孤子的碰撞进行了理论研究.运用虚时演化法数值求解了Gross-Pitaevskii方程的孤子态解,然后构造了实验中可实现的双孤子态以研究其碰撞规律.发现既存在完全弹性碰撞,也存在完全非弹性碰撞.通过调节偶极作用强度,可实现从弹性碰撞到非弹性碰撞的转变.初始时刻孤子的相位差不仅会影响系统的对称性,也会改变孤子的碰撞类型.

The collision of solitons in a quasi-one-dimensional Bose-Einstein Condensate(BEC)with dipole interaction is studied theoretically.The soliton state solution of Gross-Pitaevskii equation is obtained numerically by using the virtual time evolution method,and then the realizable double soliton state in the experiment is constructed to study the collision law.It is found that there are not only completely elastic collisions,but also completely inelastic collisions.The transition from elastic collision to inelastic collision can be achieved by adjusting the dipole interaction strength.The phase difference of solitons at the initial time will not only affect the symmetry of the system,but also change the collision type of solitons.