考虑周期性驱动线性势,利用Darboux变换法解析地研究了玻色-爱因斯坦凝聚体(BEC)中的双孤子相互作用,得到了S-波散射长度的临界值.结果表明:当S-波散射长度高于临界值时,BEC中的两个亮孤子相互吸引并融合;而当S-波散射长度低于临界值时,两个亮孤子保持局域稳定.此外,在外部势阱的驱动下,两个稳定的亮孤子产生周期性振荡行为.
Considering the periodically driving linear potential,we study the interactions between two solitons in Bose-Einstein condensate(BEC).By using Darboux transformation,the double bright soliton solution of Gross-Pitaevskii equation is obtained.Then we numerically calculate the properties of interaction between the two bright solitons in BEC,and obtain a critical value of the S-wave scattering length(SL).It is shown that,when the SL is more than the critical value,the attractive interaction and the atom transfer between two bright solitons can be observed.While the SL is less than the critical value,two bright solitons can keep stable and localized.Furthermore,the stable periodic oscillations of two solitons can be observed by slowly changing the potential.These results will be conducive to the BEC soliton experiments.