Wamba E, Sabari S, Porsezian K, Mohamadou A, Kofané T C
Department of Physics, Faculty of Science, University of Yaoundé I, P. O. Box 812, Yaoundé, Cameroon and African Institute for Mathematical Sciences, 6 Melrose Road, Muizenberg, 7945, South Africa.
Department of Physics, Pondicherry University, Puducherry 605014, India.
Phys Rev E Stat Nonlin Soft Matter Phys. 2014 May;89(5):052917. doi: 10.1103/PhysRevE.89.052917. Epub 2014 May 29.
We investigate the dynamical instability of Bose-Einstein condensates (BECs) with higher-order interactions immersed in an optical lattice with weak driving harmonic potential. For this, we compute both analytically and numerically a modified Gross-Pitaevskii equation with higher-order nonlinearity and external potentials generated by magnetic and optical fields. Using the time-dependent variational approach, we derive the ordinary differential equations for the time evolution of the amplitude and phase of modulational perturbation. Through an effective potential, we obtain the modulational instability condition of BECs and discuss the effect of the higher-order interaction in the dynamics of the condensates in presence of optical potential. We perform direct numerical simulations to support our analytical results, and good agreement is found.
我们研究了沉浸在具有弱驱动谐波势的光学晶格中的高阶相互作用玻色-爱因斯坦凝聚体（BECs）的动力学不稳定性。为此，我们通过解析和数值方法计算了一个具有高阶非线性以及由磁场和光场产生的外部势的修正格罗斯-皮塔耶夫斯基方程。使用含时变分方法，我们推导了调制微扰的振幅和相位随时间演化的常微分方程。通过一个有效势，我们得到了BECs的调制不稳定性条件，并讨论了在存在光势的情况下高阶相互作用对凝聚体动力学的影响。我们进行了直接数值模拟以支持我们的解析结果，并且发现两者吻合良好。
