研究了线性情况, 自聚焦和自散焦非线性情况下Parity-Time对称Scarff复合势中二级孤子和三级孤子的存在与稳定性.对于线性情况, 数值得到了不同调制深度下的Parity-Time对称Scarff复合势中的Parity-Time对称破坏点、本征值和多级线性模.对于非线性情况,研究了自聚焦与自散焦介质中的二级孤子和三级孤子的存在与稳定性.研究结果表明: 对于确定的调制深度, 二级线性模和三级线性模的本征值恰好等于相应的调制深度下二级孤子和三级孤子存在的临界传播常数bc.在自聚焦与自散焦介质中, 多级孤子能稳定存在于靠近临界传播常数bc的区域.

The existence and stability of dipole and tripole solitons in Parity-Time(PT) symmetric Scarff complex potentials are investigated, including linear case, and self-focusing and self-defocusing nonlinear cases. For linear case, the PT-breaking points, eigenvalues and multipole linear modes for different modulated depths of PT symmetry Scarff complex potential are obtained numerically. For nonlinear cases, the existence and stability of multipole solitons are studied in self-focusing and self-defocusing media. For a fixed modulated depth, the eigenvalue for multipole linear modes is equalt to the critical propagation constant bc of multipole solitons existence. Multipole solitons are stable with the propagation constants close to bc both for self-focusing and self-defocusing nonlinearities.