Self-localized topological states in three dimensions

TL;DR

This paper introduces self-localized topological solitons in a 3D nonlinear photonic Chern insulator, revealing how topology and nonlinearity interact to produce stable, bulk-localized states with potential for broader topological system applications.

Contribution

It proposes the existence of stable, self-localized topological solitons in 3D nonlinear photonic systems, a novel phenomenon in topological photonics.

Findings

Topological solitons are stable over a broad frequency range.

Solitons at high-symmetry points K and K' rotate in the same direction.

Topology influences the rotation and stability of the solitons.

Abstract

Three-dimensional (3D) topological materials exhibit much richer phenomena than their lower-dimensional counterparts. Here, we propose self-localized topological states (i.e., topological solitons) in a 3D nonlinear photonic Chern insulator. Despite being in the bulk and self-localized in all 3D, the topological solitons at high-symmetry points K and K' rotate in the same direction, due to the underlying topology. Specifically, under the saturable nonlinearity the solitons are stable over a broad frequency range. Our results highlight how topology and nonlinearity interact with each other and can be extended to other 3D topological systems.