arXivDaily arXiv每日学术速递 周一至周五更新
arXiv周末暂无论文更新,休息一下吧,周末愉快~~
arXiv 1805.03339cond-mat.quant-gas
收藏

谐振势中暗-亮孤子的内振荡

Internal Oscillations of a Dark-Bright Soliton in a Harmonic Potential

Majed O. D. Alotaibi, Lincoln D. Carr

摘要:

利用平均场方法,通过耦合非线性薛定谔方程,研究了多组分玻色-爱因斯坦凝聚体中的暗-亮孤子的动力学行为.我们使用一个修改后的扰动动力学变分拉格朗日近似,其中的扰动是由于陷阱,作为一个pneumas-Fermi配置文件。在标量情形下,孤子的暗分量和亮分量的波函数分别取为双曲正切解和正割解。我们还解决了这个问题的数值与伪谱龙格库塔方法。通过解析和数值计算发现,对于弱俘获,暗-亮孤子的内模几乎与其质心运动无关。相反,在较紧的陷阱的内部模式强烈耦合的质心运动,表明在谐波势的质心和相对自由度的暗亮孤子是不独立的。该结果在初始条件下对噪声是鲁棒的,因此应该是实验上可观察的。

英文摘要:

We investigate the dynamics of a dark-bright soliton in a harmonic potential using a mean-field approach via coupled nonlinear Schrödinger equations appropriate to multicomponent Bose-Einstein condensates. We use a modified perturbed dynamical variational Lagrangian approximation, where the perturbation is due to the trap, taken as a Thomas-Fermi profile. The wavefunction ansatz is taken as the correct hyperbolic tangent and secant solutions in the scalar case for the dark and bright components of the soliton, respectively. We also solve the problem numerically with psuedo-spectral Runge-Kutta methods. We find, analytically and numerically, for weak trapping the internal modes are nearly independent of center of mass motion of the dark-bright soliton. In contrast, in tighter traps the internal modes couple strongly to the center of mass motion, showing that for dark-bright solitons in a harmonic potential the center of mass and relative degrees of freedom are not independent. This result is robust against noise in the initial condition and should, therefore, be experimentally observable.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

↑