Peierls-Nabarro barrier effect in nonlinear Floquet topological insulators
Peierls-Nabarro barrier effect in nonlinear Floquet topological insulators
复制标题
非线性 Floquet 拓扑绝缘体中的 Peierls-Nabarro 势垒效应
DOI：
10.1103/physreve.103.042214
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发表时间：
2021
影响因子：
2.4
通讯作者：
Rosenthal, Peter
中科院分区：
文献类型：
--
作者：
Ablowitz, Mark J.;Cole, Justin T.;Hu, Pipi;Rosenthal, Peter
Peierls-Nabarro势垒是离散非线性系统中经常出现的一种离散效应。障碍的一个标志是离散孤立波的减慢和最终停止。这项工作探讨了强烈的电磁波传播通过周期性蜂窝晶格的螺旋驱动波导，作为一个范例Floquet拓扑绝缘体。这里它表明，离散拓扑保护的边缘modesdo不遭受典型的Peierls-Nabarro障碍相关的减速。相反，由于它们的拓扑性质，模式总是向前移动并重新分配它们的能量：一个窄的（离散的）模式转变为一个宽的有效连续的模式。另一方面，不受拓扑保护的离散边缘模式最终会减慢并停止传播。最初很窄的拓扑模自然倾向于由广义非线性薛定谔方程描述的宽包络状态。这些结果提供了深入了解的性质，非线性拓扑绝缘体及其应用。
The Peierls-Nabarro barrier is a discrete effect that frequently occurs in discrete nonlinear systems. A signature of the barrier is the slowing and eventual stopping of discrete solitary waves. This work examines intense electromagnetic waves propagating through a periodic honeycomb lattice of helically driven waveguides, which serves as a paradigmatic Floquet topological insulator. Here it is shown that discrete topologically protected edge modesdo notsuffer from the typical slowdown associated with the Peierls-Nabarro barrier. Instead, as a result of their topological nature, the modes always move forward and redistribute their energy: a narrow (discrete) mode transforms into a wide effectively continuous mode. On the other hand, a discrete edge mode that isnottopologically protecteddoeseventually slow down and stop propagating. Topological modes that are initially narrow naturally tend to wide envelope states that are described by a generalized nonlinear Schrödinger equation. These results provide insight into the nature of nonlinear topological insulators and their application.