一维简谐势阱中超冷费米气体的孤子解及其稳定性  

Soliton solutions and stability of ultracold fermionic gas in a one-dimensional harmonic well

作　　者：徐红萍[1] 刘巧娟 唐荣安[1] 贺真真 XU Hong-ping;LIU Qiao-juan;TANG Rong-an;HE Zhen-zhen(College of Physics and Electronic Engineering,Northwest Normal University,Lanzhou 730070,Gansu,China)

机构地区：[1]西北师范大学物理与电子工程学院,甘肃兰州730070

出　　处：《西北师范大学学报（自然科学版）》2021年第3期52-56,共5页Journal of Northwest Normal University(Natural Science)

基　　金：国家自然科学基金资助项目(11764039,11305132,11274255)。

摘　　要：利用虚时演化算法研究了准一维简谐势阱中的超冷费米气体,发现在超冷费米气体的不同超流态上孤子空间分布存在明显的差异.在BCS端,随着弱吸引相互作用逐渐增大,孤子的峰值不断增大,宽度不断变小;在分子BEC端,随着弱排斥相互作用逐渐增大,孤子的峰值不断减小,宽度不断增大;并且在BCS端的孤子峰值大于分子BEC端孤子的峰值,而孤子宽度却小于分子BEC端的孤子宽度.此外,通过非线性实时演化方法对超冷费米气体中孤子的稳定性进行了分析,即使给波函数乘以一个强扰动因子,不同超流态上的孤子依然能够稳定传播.In this paper,the imaginary-time evolution algorithm is used to study ultracold fermionic gas in the quasi-one-dimensional harmonic potential,and it is found that there are obvious differences in the spatial distribution of solitons in different superfluid states:in the BCS side,with the weakly attractive interaction gradually increases,the peak value of the solitons increases and the width decreases;in the molecular BEC side,with the weakly repulsive interaction increases,the peak value of the soliton decreases and the width increases.Moreover,the peak value of solitons in the BCS side is larger than in the molecular BEC side,and the width of solitons in the BCS side is smaller than in the molecular BEC side.In addition,the stability of solitons in a ultracold Fermi gas is also analyzed by using the nonlinear real-time evolution method.A rather strong perturbation was applied to the soliton.The perturbed soliton in different superfluid states remains stable.

关 键 词：孤波解 虚(实)时演化法 费米气体 

分 类 号：O469[理学—凝聚态物理]