Edge modes of chiral Berry plasmons in graphene nanoribbons

摘要

This study examines the edge modes of chiral Berry plasmons propagating along zigzag or armchair edges of a graphene nanoribbon under a finite Berry flux and Fermi pressure. A two-dimensional quantum hydrodynamic model is used to derive analytical expressions of the dispersion relation and transverse confinement length. Direction-dependent edge modes exist in armchair nanoribbons under antisymmetric or symmetric boundary conditions. A confined mode appears in the zigzag nanoribbon under hard-wall boundary conditions. The transverse confinement length of edge plasmons in the nanoribbon can be an order of magnitude shorter than that in the semi-infinite structure.