Institut für Physik, Universität Rostock, Albert-Einstein-Str. 23, 18059 Rostock, Germany.
Moscow Institute of Physics and Technology, Institutsky lane 9, Dolgoprudny, Moscow Region 141700, Russia.
Science. 2020 Nov 6;370(6517):701-704. doi: 10.1126/science.abd2033.
A hallmark feature of topological insulators is robust edge transport that is impervious to scattering at defects and lattice disorder. We demonstrate a topological system, using a photonic platform, in which the existence of the topological phase is brought about by optical nonlinearity. The lattice structure remains topologically trivial in the linear regime, but as the optical power is increased above a certain power threshold, the system is driven into the topologically nontrivial regime. This transition is marked by the transient emergence of a protected unidirectional transport channel along the edge of the structure. Our work studies topological properties of matter in the nonlinear regime, providing a possible route for the development of compact devices that harness topological features in an on-demand fashion.
拓扑绝缘体的一个显著特点是其边缘传输具有鲁棒性，不受缺陷和晶格无序的散射影响。我们使用光子平台展示了一个拓扑系统，其中拓扑相的存在是由光学非线性引起的。在线性区域，晶格结构在拓扑上是平凡的，但随着光功率增加到超过某个功率阈值，系统被驱动到非平凡的拓扑区域。这种转变的标志是结构边缘出现一个受保护的单向传输通道。我们的工作研究了物质在非线性区域的拓扑性质，为开发以按需方式利用拓扑特性的紧凑型设备提供了一种可能的途径。
