We find that the Berry curvature splits the edge plasmons propagating along the opposite directions in quantum anomalous Hall insulators even with vanishing Chern number. When the bulk is insulating, a single unidirectional edge plasmon survives and becomes acoustic in the long-wavelength limit, which coincides with recent experiments. The group velocity of the chiral edge plasmon would change its sign for a large wave vector and exhibit the unusual negative dispersion, which originates from the $k^2$ correction to the effective mass. The impacts of the Fermi level and the wave vector on the bulk and edge plasmons are discussed. Our work provides a very quantitative explanation of the recent observation of the chiral edge plasmon in quantum anomalous Hall insulators and some insight into the application of realistic topological materials in chiral plasmonics.

Close

PrevNext

View figure in article

• Geometric & topological phases
• Plasmons
• Quantum anomalous Hall effect