Nonlinearity-induced photonic topological insulator

The hallmark feature of topological insulators renders edge transport virtually impervious to scattering at defects and lattice disorder. In our work, we experimentally demonstrate a topological system, using a photonic platform, in which the very existence of the topological phase is brought about by nonlinearity. Whereas in the linear regime, the lattice structure remains topologically trivial, light beams launched above a certain power threshold drive the system into its transient topological regime, and thereby define a nonlinear unidirectional channel along its edge. Our work studies topological properties of matter in the nonlinear regime, and may pave the way towards compact devices that harness topological features in an on-demand fashion

High-Dimensional Synthetic Lattice With Enhanced Defect Sensitivity In Planar Photonic Structures

We introduce a general method to map multi-dimensional lattices to planar photonic structures, and predict a sharp switching from zero to strong localization at a critical surface defect strength in four and higher-dimensional synthetic lattices