玻色爱因斯坦凝聚中对暗孤子的KdV方程描述

KdV Description of Dark Solitons in Bose-Einstein Condensation(BEC)

以平均场理论为基础,结合玻色-爱因斯坦凝聚的性质,通过两模近似,对超流气体在unitarity区域和BEC区域的限制条件下,研究了波色超流气体中的一维孤立波脉冲.运用约化摄动法得到了电子声孤波的KdV方程,从而得到一孤波解.发现孤立子的传播振幅和宽度与参量c_0,c_1,γ,γ_0,γ_1,以及散射长度a有关.

A one‐dimensional solitary wave pulse in the superfluid Bose gas under the limiting conditions of unitarity region and BEC region is studied ,based on the mean‐field theory in combination with the proper‐ty of Bose‐Einstein condensation and through the two‐mode approximation .By using the reductive pertur‐bation method ,a (KdV) equation for the nonlinear electron‐acoustic solitary waves is derived ,from which a solitary wave solution is obtained .It is found that the amplitude and width of the solitary waves depend on the parameters c ,c0 ,c1 ,γ,γ0 and γ1 and on the scattering length a .