We analyze the stability of extended edge modes in a nonlinear (i.e., interacting) bosonic topological insulator. We see that these nonlinear modes are always unstable, despite the topological protection of edge modes in the linear system. For concreteness we use a photonic platform, but the results generalize to other bosonic systems. We give a detailed description of the system in two extreme cases, low nonlinearity and high nonlinearity, and discuss the breakup of the nonlinear edge states into solitons.
All Science Journal Classification (ASJC) codes
- Atomic and Molecular Physics, and Optics