深光晶格势阱中凝聚体的扭结包络隙孤子

发展准离散多尺度法结合紧束缚近似,解析地研究了局陷于光晶格势阱中凝聚体的非线性动力学性质.结果发现,系统中出现稳定的对称包络孤子外,还可观察到一种新的非线性元激发:扭结包络隙孤子.有趣的是,该隙孤子并不传播且局域在初始位置,其幅度可通过光晶格势阱的晶格常数和势阱深度来调控.相应的实验方案是:通过改变形成光晶格势阱的两交叉耦合激光束之间的夹角和(或)激光光强来调控扭结包络隙孤子的幅度.

Kink-envelope gap soliton of the condensates trapped in the deep optical lattices

By developing quasi-discrete multiple-scale method combined with tight-binding approximation, the nonlinear dynamical properties of the condensates trapped in the optical lattices are studied analytically. It is shown that besides the usual symmetric envelope soliton appears in this system, a novel nonlinear elementary excitation, kink-envelope gap soliton, is also observed. Interestingly, these solitons are non-propagation and localize at initial position. Furthermore, the amplitude of the kink-envelope gap soliton can be adjusted by the lattice spacing and depth of the optical lattices. Accordingly, we provide experimental protocols to control the amplitude of the kink-envelope soliton by varying the angle and/or light intensity between the intersecting laser beams forming the optical lattice.