Decay dynamics of topological valley-Hall edge states in multicomponent diffusive systems

Triggered by the discovery of topological insulators, applications that utilize topological properties are extended to diffusion systems. In this study, we investigate the decay dynamics of topological valley-Hall edge states in systems containing multiple interactive diffusive quantities. We find that the interaction between the diffusive quantities lifts the degeneracy of the edge modes, splitting them into fast-decaying and slow-decaying modes. In addition, our analysis reveals that the eigenfunctions of the edge modes have different polarities, resulting in attraction and repulsion between the two diffusive quantities, depending on the excited modes. These findings suggest the possibility of tailoring decay rates in multicomponent diffusive systems.