深圳大学李朝红团队的最新研究发现了边缘孤子的非线性拓扑泵浦。这一研究成果发表在2025年3月11日出版的《物理评论A》杂志上。

研究组利用Gross-Pitaevskii方程研究了非线性强度如何影响边缘孤子的拓扑泵浦。对于弱非线性强度，非线性的引入破坏了能谱的对称性，这使得从左边缘到右边缘的拓扑泵浦与逆过程不同。对于中等的非线性强度，谱中出现了自交叉结构，从右到左的绝热泵浦通道被破坏，在缓慢调制下只能实现从左到右的拓扑泵浦。

随着非线性强度的进一步增加，尽管一个泵浦周期中的从左到右拓扑泵浦也会失效，但研究组发现位于单个左边缘的薄孤子可以与体孤子混合，并且可以在多个泵浦周期后实现边缘和体孤子的混合拓扑泵浦。为了获得更强的非线性强度，边缘孤子被自陷，所有拓扑泵浦通道都被关闭。该工作可能会引发对非线性和拓扑之间相互作用的进一步研究。

附：英文原文

Title: Nonlinear topological pumping of edge solitons

Author: Xinrui You, Liaoyuan Xiao, Boning Huang, Yongguan Ke, Chaohong Lee

Issue&Volume: 2025/03/11

Abstract: We study how nonlinear strength affects topological pumping of edge solitons by using the Gross–Pitaevskii equation. For weak nonlinear strength, the introduction of nonlinearity breaks the symmetry of the energy spectrum, which makes the topological pumping from the left edge to the right edge differ from the inverse process. For moderate nonlinear strength, self-crossing structures appear in the spectrum, and the right-to-left adiabatic pumping channel is destroyed, only left-to-right topological pumping can be achieved under slow modulation. As the nonlinear strength further increases, although left-to-right topological pumping in one pumping cycle also breaks down, we find that a thin soliton, located at a single left edge, can be mixed with the bulk soliton, and hybridized topological pumping of edge and bulk solitons can be realized after multiple pumping cycles. For stronger nonlinear strength, edge solitons are self-trapped and all topological pumping channels are shut down. Our work could trigger further studies of the interplay between nonlinearity and topology.

DOI: 10.1103/PhysRevA.111.033306

Source: https://journals.aps.org/pra/abstract/10.1103/PhysRevA.111.033306